<PAGE>

      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 15, 2005

                                                      REGISTRATION NO. 333-_____
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                       ----------------------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                                    SPSS INC.
              ----------------------------------------------------
             (Exact name of Registrant as specified in its charter)

              DELAWARE                                36-2815480
   -------------------------------                ------------------
   (State or other jurisdiction of                 (I.R.S. Employer
   incorporation or organization)                 Identification No.)

                             233 SOUTH WACKER DRIVE
                             CHICAGO, ILLINOIS 60606
                                 (312) 651-3000
   --------------------------------------------------------------------------
  (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF
                   REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

                                    SPSS INC.
                          EMPLOYEE STOCK PURCHASE PLAN

                                RAYMOND H. PANZA
                 EXECUTIVE VICE PRESIDENT, CORPORATE OPERATIONS,
                      CHIEF FINANCIAL OFFICER AND SECRETARY
                                    SPSS Inc.
                             233 South Wacker Drive
                                   11th Floor
                             Chicago, Illinois 60606
                                 (312) 651-3000
             --------------------------------------------------------
            (Name, address, including zip code, and telephone number,
                   including area, code, of agent for service)

                                   Copies to:

                            Lawrence R. Samuels, Esq.
                                McGuireWoods LLP
                              77 West Wacker Drive
                                   Suite 4100
                             Chicago, Illinois 60601
                                 (312) 849-8100

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                                            Proposed
                                        Amount               maximum                Proposed               Amount of
          Title of                       to be            offering price           aggregate              registration
 Securities to be registered         registered(1)         per share(2)        offering price(3)              fee
 ----------------------------        ------------         --------------       ----------------           ------------
<S>                                  <C>                  <C>                  <C>                        <C>
Common Stock, $0.01 par value           500,000               $18.05              $9,025,000               $1,062.24
                                        =======               ======              ==========               =========
</TABLE>

      (1) The securities being registered include a maximum of 500,000 shares
issuable pursuant to the SPSS Inc. Employee Stock Purchase Plan assuming full
participation of employees under that plan.

      (2) Solely for the purpose of calculating the registration fee, the
offering price per share, the aggregate offering price and the amount of the
registration fee have been computed in accordance with Rule 457(c) under the
Securities Act of 1933. Accordingly, the price per share of common stock has
been calculated to be equal to the average of the high and low prices for a
share of common stock as reported by the NASDAQ National Market on June 10,
2005, which is a specified date within five business days prior to the original
date of filing of this Registration Statement.

      (3) Solely for the purpose of calculating the registration fee, the
proposed aggregate offering price has been estimated in accordance with Rule
457(h) promulgated under the Securities Act of 1933.

<PAGE>

                                EXPLANATORY NOTE

This registration statement registers:

      -     Shares of common stock that may be issued upon the purchase of
            shares pursuant to the SPSS Inc. Employee Stock Purchase Plan
            (referred to as the "Stock Purchase Plan");

      -     Certain resales of shares of common stock that may be issued upon
            the purchase of shares pursuant to the Stock Purchase Plan.

      This registration statement contains two parts. The first part contains a
reoffer prospectus prepared in accordance with Part I of Form S-3, pursuant to
General Instruction C to Form S-8. The reoffer prospectus may be used for
reoffers or resales of the shares that have been acquired by the selling
stockholders. The second part contains information required in the registration
statement under Part II of Form S-8.

      The information specified by Part I of Form S-8 is not being filed with
the Securities and Exchange Commission as permitted by the Note in Part I of
Form S-8. This information will be sent or given to the participants in the
Stock Purchase Plan as specified by Rule 428(b)(1) under the Securities Act of
1933.

<PAGE>

                               REOFFER PROSPECTUS

                                    SPSS INC.

                                  Common Stock

      This reoffer prospectus relates to an offering of shares of common stock
of SPSS Inc. (referred to as "SPSS" or the "Company") which may be issued upon
the purchase of shares by certain selling stockholders pursuant to the SPSS Inc.
Employee Stock Purchase Plan (referred to as the "Stock Purchase Plan").

      The common stock being registered may be offered for the account of the
stockholders, who may from time to time be identified under the section heading
"SELLING STOCKHOLDERS" in a supplement to this reoffer prospectus. The selling
stockholders will receive all of the proceeds from any sales of the shares of
SPSS common stock offered under this reoffer prospectus. Although SPSS will not
receive any proceeds from the selling stockholders' sale of shares of the
Company's common stock offered under this reoffer prospectus, SPSS will receive
proceeds from the initial cash purchase of its common stock by the selling
stockholders under the Stock Purchase Plan. All proceeds received as a result of
the purchase of SPSS common stock under the Stock Purchase Plan will be used as
working capital for the Company's operations.

      The shares of SPSS common stock issued to the selling stockholders are
being registered to permit the selling stockholders to sell the shares from time
to time in the public market. The selling stockholders may sell the shares of
SPSS common stock on the Nasdaq National Market, in negotiated transactions, or
through a combination of these methods, at prevailing market prices or at
privately negotiated prices, either directly or through agents or
broker-dealers, or through any other means described in the section titled "PLAN
OF DISTRIBUTION," beginning on Page 10.

      The Company's common stock is quoted on the Nasdaq National Market under
the symbol "SPSS." On June 14, 2005, the last reported sale price of SPSS common
stock on the Nasdaq National Market was $18.48 per share. Our address is
233 South Wacker Drive, 11th Floor, Chicago, Illinois 60606 and our phone number
is (312) 651-3000.

      The shares offered by means of this reoffer prospectus involve a high
degree of risk. Eligible persons should participate in the Stock Purchase Plan
and purchase shares of SPSS common stock only if they can afford a loss of all
or a portion of the investment in those shares. SEE "RISK FACTORS" BEGINNING ON
PAGE 2.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THE COMMON STOCK TO WHICH THIS REOFFER
PROSPECTUS RELATES OR PASSED UPON THE ADEQUACY OR ACCURACY OF THIS REOFFER
PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

              The date of this reoffer prospectus is June 15, 2005.

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                Page
                                                                ----
<S>                                                             <C>
FORWARD-LOOKING STATEMENTS.................................       1

RISK FACTORS...............................................       2

USE OF PROCEEDS............................................       9

SELLING STOCKHOLDERS.......................................       9

PLAN OF DISTRIBUTION.......................................      10

LEGAL MATTERS..............................................      11

EXPERTS....................................................      11

WHERE INVESTORS CAN FIND MORE INFORMATION..................      12

INFORMATION INCORPORATED BY REFERENCE......................      12
</TABLE>

                                       i

<PAGE>

                           FORWARD-LOOKING STATEMENTS

      THIS REOFFER PROSPECTUS CONTAINS FORWARD-LOOKING STATEMENTS WITHIN THE
MEANING OF SECTION 27A OF THE SECURITIES ACT OF 1933 AND SECTION 21E OF THE
SECURITIES EXCHANGE ACT OF 1934. SPSS MAY ALSO MAKE WRITTEN FORWARD-LOOKING
STATEMENTS IN ITS PERIODIC REPORTS TO THE SECURITIES AND EXCHANGE COMMISSION, IN
ITS PRESS RELEASES AND OTHER WRITTEN MATERIALS AND IN ORAL STATEMENTS MADE BY
ITS OFFICERS, DIRECTORS OR EMPLOYEES TO THIRD PARTIES. STATEMENTS THAT ARE NOT
HISTORICAL FACTS, INCLUDING, WITHOUT LIMITATION, STATEMENTS REGARDING THE
COMPANY'S EXPECTATIONS, BELIEFS, INTENTIONS OR FUTURE STRATEGIES, ARE
FORWARD-LOOKING STATEMENTS. THESE STATEMENTS ARE BASED ON THE BELIEFS AND
ASSUMPTIONS OF SPSS MANAGEMENT AND ON INFORMATION CURRENTLY AVAILABLE TO THE
COMPANY. FORWARD-LOOKING STATEMENTS INCLUDE STATEMENTS PRECEDED BY, FOLLOWED BY
OR THAT INCLUDE THE WORDS "EXPECTS," "ANTICIPATES," "INTENDS," "BELIEVES,"
"PLANS," "ESTIMATES," "DESIGNED," "MAY," COULD," "PREDICTS" OR SIMILAR LANGUAGE.

      ALL FORWARD-LOOKING STATEMENTS INCLUDED IN THIS DOCUMENT ARE BASED ON
INFORMATION AVAILABLE TO SPSS ON THE DATE HEREOF. THE COMPANY CAUTIONS INVESTORS
THAT ITS BUSINESS AND FINANCIAL PERFORMANCE AND THE MATTERS DESCRIBED IN THESE
FORWARD-LOOKING STATEMENTS ARE SUBJECT TO SUBSTANTIAL RISKS AND UNCERTAINTIES.
THE COMPANY'S FUTURE RESULTS MAY DIFFER MATERIALLY FROM THOSE EXPRESSED IN THE
FORWARD-LOOKING STATEMENTS CONTAINED IN THIS REOFFER PROSPECTUS AND IN THE
INFORMATION INCORPORATED BY REFERENCE IN THIS REOFFER PROSPECTUS (SEE "WHERE YOU
CAN FIND MORE INFORMATION"). A NUMBER OF IMPORTANT FACTORS COULD CAUSE ACTUAL
RESULTS TO DIFFER MATERIALLY FROM THOSE CONTAINED IN ANY FORWARD-LOOKING
STATEMENT. SPECIFIC FACTORS THAT MIGHT CAUSE THESE DIFFERENCES ARE DISCUSSED
THROUGHOUT THIS REOFFER PROSPECTUS, INCLUDING IN THE SECTION ENTITLED "RISK
FACTORS." IN ADDITION, FOR FURTHER INFORMATION REGARDING THESE RISKS AND
UNCERTAINTIES, PLEASE REFER TO PUBLICLY AVAILABLE DOCUMENTS THAT SPSS HAS FILED
WITH THE SECURITIES AND EXCHANGE COMMISSION.

      BECAUSE OF THESE RISKS AND UNCERTAINTIES, SOME OF WHICH MAY NOT BE
CURRENTLY ASCERTAINABLE AND MANY OF WHICH ARE BEYOND THE COMPANY'S CONTROL,
ACTUAL RESULTS COULD DIFFER MATERIALLY FROM THOSE PROJECTED IN THE
FORWARD-LOOKING STATEMENTS. DEVIATIONS BETWEEN ACTUAL FUTURE EVENTS AND THE
COMPANY'S ESTIMATES AND ASSUMPTIONS COULD LEAD TO RESULTS THAT ARE MATERIALLY
DIFFERENT FROM THOSE EXPRESSED IN OR IMPLIED BY THE FORWARD LOOKING STATEMENTS.
SPSS DOES NOT INTEND TO UPDATE THESE FORWARD LOOKING STATEMENTS TO REFLECT
ACTUAL FUTURE EVENTS.

                                       1

<PAGE>

                                  RISK FACTORS

      Potential investors should carefully consider the risks described below
before making an investment decision. The risks and uncertainties described
below are not the only ones facing SPSS. Additional risks and uncertainties not
presently known to SPSS, or those it currently believes are immaterial, could
also impair its business operations. If any of the following risks actually
occurred, the business and financial conditions of SPSS or the results of its
operations could be materially adversely affected, the trading price of SPSS
common stock could decline, and investors could lose all or part of their
investment in the Company.

               THE COMPANY'S FINANCIAL RESULTS AND STOCK PRICE MAY
                      BE AFFECTED BY QUARTERLY FLUCTUATIONS

      The quarterly revenue and operating results of SPSS have varied in the
past and may continue to do so in the future. Future revenues and operating
results will depend upon, among other factors:

      -     the number and timing of product updates and new product
            introductions;

      -     delays in product development and introduction;

      -     purchasing schedules of the Company's customers;

      -     changes in foreign currency exchange rates;

      -     changes in prescribed accounting rules and practices;

      -     product and market development expenditures;

      -     the timing of product shipments;

      -     changes in the Company's product mix;

      -     timing, costs and effects of acquisitions; and

      -     general economic conditions.

      Because expense levels are to a large extent based on its forecasts of
future revenues, the Company's operating results may be adversely affected if
our future revenues fall below expectations. Accordingly, SPSS believes that
quarter-to-quarter comparisons of its results of operations may not be
meaningful and should not be relied upon as an indication of future performance.

      SPSS has historically operated with very little backlog because its
products are generally shipped as orders are received. As a result, revenues in
any quarter are dependent on orders shipped and licenses renewed in that
quarter. SPSS has experienced a seasonal pattern in its operating results, with
the fourth quarter typically having the highest operating income.

      In addition, the timing and amount of the Company's revenues may be
affected by a number of factors that make estimation of operating results before
the end of a quarter uncertain. A significant portion of the Company's operating
expenses are relatively fixed, and planned expenditures are based primarily on
revenue forecasts. The variable profit margins on modest increases in sales
volume at the end of fiscal quarters are significant and, should SPSS fail to
achieve these revenue increases, net income could be materially affected.
Generally, if revenues do not meet its expectations in any given quarter, the
Company's operating results will be adversely affected. There can be no
assurance that profitability on a quarterly or annual basis can be achieved or
sustained in the future.

                                       2

<PAGE>

                    THE ANTICIPATED BENEFITS OF THE COMPANY'S
                        ACQUISITIONS MAY NOT MATERIALIZE

      In recent years, SPSS has made a significant number of acquisitions,
including the acquisition of businesses based outside of the United States. Part
of the Company's growth strategy includes pursuing additional acquisitions. Any
of these transactions could be material to the Company's financial condition and
results of operations. In addition, the process of integrating an acquired
company, business or technology involves risk and may create unforeseen
operating difficulties and expenditures. These areas of risk include:

      -     the need to implement or remediate controls, procedures and policies
            at companies that, prior to the acquisition, lacked these controls,
            procedures and policies;

      -     interruption of, or a distraction of management's attention from,
            the Company's business;

      -     cultural challenges associated with integrating employees from the
            acquired company into the SPSS organization; and

      -     the need to integrate each company's accounting, management
            information, human resource and other administrative systems to
            permit effective management.

      Foreign acquisitions involve unique risks in addition to those mentioned
above, including those related to the integration of operations across different
cultures and languages, currency risks and the particular economic, political
and regulatory risks associated with specific countries.

      We may not be able to consummate these potential future acquisitions on
terms acceptable to us, or at all. Further, the anticipated benefit of many of
our acquisitions may not materialize. Future acquisitions or dispositions could
result in potentially dilutive issuances of our equity securities, the
incurrence of debt, contingent liabilities or amortization expenses, or
write-offs of goodwill, any of which could harm our financial condition. Any of
these events could have a material adverse effect on SPSS.

                       SPSS MAY NOT RESPOND ADEQUATELY TO
                           RAPID TECHNOLOGICAL CHANGES

      The computer software industry is characterized by rapid technological
advances, changes in customer requirements, as well as frequent enhancements to
and introductions of technologies. The future success of SPSS will depend upon
its ability to enhance its existing software and introduce new software products
that keep pace with technological developments, respond to evolving customer
requirements and achieve market acceptance. In particular, SPSS believes it must
continue to respond quickly to users' needs for greater functionality, improved
usability and support for new hardware and operating systems. Any failure by
SPSS to respond adequately to technological developments and customer
requirements, or any significant delays in software development or introduction,
could result in loss of revenues.

      In the past, SPSS has, on occasion, experienced delays in the introduction
of new software and enhancements to existing technology, primarily due to
difficulties with particular operating environments and problems with software
provided by third parties. The extent of these delays has varied depending upon
the size and scope of the project and the nature of the problems encountered.
These delays have most often resulted from "bugs" encountered in working with
new versions of

                                       3

<PAGE>

operating systems and other third party software, and "bugs" or unexpected
difficulties in existing third party software which complicate integration with
SPSS software. From time to time, SPSS has discovered "bugs" in its software
that are resolved through maintenance releases or through periodic updates
depending upon the seriousness of the defect. There can be no assurance that
SPSS will be successful in developing and marketing new software or enhancements
to existing technology on a timely basis or that SPSS will not experience
significant delays or defects in its software in the future, which could have a
material adverse effect on SPSS. In addition, there can be no assurance that new
software or enhancements to existing technology developed by SPSS will achieve
market acceptance or that developments by others will not render SPSS
technologies obsolete or noncompetitive.

                     SPSS MAY FACE BUSINESS DECLINES DUE TO
                          OUR INTERNATIONAL OPERATIONS

      Revenues from operations outside of North America accounted for
approximately 49% of the Company's total revenues in 2002, 51% in 2003, and 55%
in 2004. SPSS expects that revenues from international operations will continue
to represent a large percentage of its net revenues and that this percentage may
increase, particularly as SPSS further "localizes" products by translating them
into additional languages and expands its operations through acquisitions of
companies outside the United States. A number of risk factors may affect the
Company's international revenues, including:

      -     greater difficulties in accounts receivable collection;

      -     longer payment cycles;

      -     exposure to currency fluctuations;

      -     political and economic instability; and

      -     the burdens of complying with a wide variety of foreign laws and
            regulatory requirements.

      SPSS also believes that it is exposed to greater levels of software piracy
in certain international markets where weaker protection is afforded to
intellectual property. As SPSS expands its international operations, the risks
described above could increase and, in any event, could have a material adverse
effect on SPSS.

                 THE SPSS STOCK PRICE MAY EXPERIENCE VOLATILITY

      There has been significant volatility in the market prices of securities
of technology companies, including SPSS, and, in some instances, this volatility
has been unrelated to the operating performance of those companies. Market
fluctuations may adversely affect the price of the Company's common stock. SPSS
also believes that, in addition to factors such as interest rates and economic
conditions which affect stock prices generally, some, but not all, of the
factors which could result in fluctuations in its stock price include:

      -     announcements of new products by SPSS or its competitors;

      -     quarterly variations in financial results;

      -     recommendations and reports of analysts;

      -     acquisitions; and

      -     other factors beyond the control of SPSS.

                                       4

<PAGE>

                SPSS RELIES ON THIRD PARTIES FOR CERTAIN SOFTWARE

      SPSS licenses software from third parties. Some of this licensed software
is embedded in the Company's products, and some is offered as add-on products.
If these licenses are discontinued, or become invalid or unenforceable, there
can be no assurance that SPSS will be able to develop substitutes for this
software independently or to obtain alternative sources in a timely manner. Any
delays in obtaining or developing substitutes for licensed software could have a
material adverse effect on SPSS.

             SPSS RELIES ON THIRD PARTIES FOR SOFTWARE DISTRIBUTION

      In January 1997, SPSS entered into the Banta Global Turnkey Software
Distribution Agreement under which Banta Global Turnkey manufactures, packages
and distributes the Company's software products to the Company's domestic and
international customers and various international subsidiaries. The Banta
agreement had an initial three-year term and automatically renews thereafter for
successive periods of one year. The Banta agreement was renewed in January 2004.
Either party may terminate the Banta agreement for cause by written notice if
the other materially breaches its obligations. If Banta fails to perform
adequately any of its obligations under the Banta agreement, the Company's
operating results could be materially adversely affected.

                         CHANGES IN PUBLIC EXPENDITURES
                            MAY ADVERSELY AFFECT SPSS

      A significant portion of the revenues of SPSS comes from licenses of its
software directly to government entities both internationally and in the United
States. In addition, significant amounts of the Company's revenues come from
licenses to academic institutions, healthcare organizations and private
businesses that contract with or are funded by government entities. Government
appropriations processes are often slow and unpredictable and may be affected by
factors outside the Company's control. In addition, proposals are currently
being made in various countries to reduce government spending. Reductions in
government expenditures and termination or renegotiation of government-funded
programs or contracts could have a material adverse effect on SPSS. In addition,
declines in overall levels of economic activity could also have a material
adverse impact on SPSS.

                 SPSS MAY BE UNABLE TO CONTINUE TO COMPETE WITH
                 COMPANIES IN ITS INDUSTRIES THAT HAVE FINANCIAL
                               OR OTHER ADVANTAGES

      The Company's historical market for statistical software is both highly
competitive and fragmented. SPSS is among the largest companies in the
statistical software market, and, based upon sales and comparative assessments
in trade publications, SPSS believes that it competes effectively against its
competitors. SPSS considers its primary worldwide competitor to be the larger
and better-financed SAS Institute, although SPSS believes that the SAS
Institute's revenues are derived primarily from offerings in areas other than
predictive analytics. StatSoft Inc., Minitab Inc., Stata and Insightful are also
competitors, although their annual revenues from statistical products are
believed to be considerably less than the revenues of SPSS. In addition to
competition from other statistical software companies, SPSS also faces
competition from providers of software for specific statistical applications.

      In the market for data mining tools, the Company also competes with
offerings from Oracle, NCR, Fair Isaac, Angoss and Quadstone. In the market for
predictive analytic applications, SPSS also faces competition from well-financed
companies such as Siebel Systems, PeopleSoft, Fair Isaac and E.piphany. With the
exception of the SAS Institute, none of the Company's competitors are believed
to currently offer the range of predictive analytical capability provided by
SPSS.

                                       5

<PAGE>

      SPSS holds a strong position in the market for analytic applications to
the market research industry. SPSS believes no competitors in this market are
larger and better financed. The annual revenues of competitors such as Pulse
Train Technology, The Firm, Sawtooth Software, and Computers for Marketing
Corporation are thought to be considerably less than the market research
revenues of SPSS.

      In all markets, SPSS competes primarily on the basis of the usability,
functionality, performance, reliability and connectivity of its software. The
significance of each of these factors varies depending upon the anticipated use
of the software and the analytical training and expertise of the customer. To a
lesser extent, SPSS competes on the basis of price and thus maintains pricing
and licensing policies to meet market demand. SPSS believes it is able to
compete successfully because of the highly usable interfaces, comprehensive
analytical capabilities, efficient performance characteristics, local language
versions, consistent quality, connectivity capabilities, worldwide distribution
capabilities and widely recognized brand names.

      In the future, SPSS may face competition from new entrants into its
markets. SPSS could also experience competition from companies in other sectors
of the broader market for business intelligence software, like providers of OLAP
(On-Line Analytical Processing) and analytical application software, as well as
from companies in other sectors of the broader market for enterprise
applications, which could add enhanced analytical functionality to their
existing products. Some of these potential competitors have significant capital
resources, marketing experience and research and development capabilities.
Competitive pressures from the introduction of new solutions and products by
these companies or other companies could have a material adverse effect on SPSS.
There can be no assurance that SPSS will be able to compete successfully in the
future.

                 SPSS DEPENDS ON KEY EXECUTIVES; A LOSS OF THESE
                 EXECUTIVES AND OTHER PERSONNEL COULD NEGATIVELY
                              IMPACT OUR OPERATIONS

      SPSS is dependent on the efforts of various executives and key employees,
including its President and Chief Executive Officer, Jack Noonan. The continued
success of SPSS will depend in part on its ability to attract and retain highly
qualified technical, managerial, sales, marketing and other personnel.
Competition for highly qualified personnel is intense. The inability of SPSS to
continue to attract or retain highly qualified personnel could have a material
adverse effect on its financial position and results of operation. No life
insurance policies are maintained on SPSS key personnel.

                    SPSS MAY NOT RECEIVE THE FULL BENEFITS OF
                      ITS INTELLECTUAL PROPERTY PROTECTIONS

      The analytical algorithms incorporated in SPSS software are not
proprietary. SPSS believes that the proprietary technology constituting a
portion of its software determines the speed and quality of displaying the
results of computations, the ability of its software to work in conjunction with
third party software, and the ease of use of its software. The success of SPSS
will depend, in part, on its ability to protect the proprietary aspects of its
software. Attempts by SPSS to protect its proprietary software with trade secret
laws and internal nondisclosure safeguards, as well as copyright, trademark and
patent laws and contractual restrictions on copying, disclosure and
transferability that are incorporated into its software license agreements. SPSS
licenses its software only in the form of executable code, with contractual
restrictions on copying, disclosures and transferability. Except for licenses of
its products to users of large system products and annual licenses of its
desktop products, SPSS licenses its products to end-users by use of a
"shrink-wrap" license, as is customary in the industry. The source code for all
of

                                       6

<PAGE>

SPSS software is protected as a trade secret and as unpublished copyrighted work
or patents. In addition, SPSS has entered into confidentiality and nondisclosure
agreements with its key employees. Despite these restrictions, the possibility
exists for competitors or users to copy aspects of SPSS products or to obtain
information which SPSS regards as a trade secret. Preventing unauthorized use of
computer software is difficult, and software piracy is expected to be a
persistent problem for the packaged software industry. These problems may be
particularly acute in international markets. In addition, the laws of various
countries in which SPSS software is or may be licensed do not protect its
software and intellectual property rights to the same extent as the laws of the
United States. Despite the precautions taken by SPSS, it may be possible for
unauthorized third parties to reverse engineer or copy SPSS products or obtain
and use information that SPSS regards as proprietary. There can be no assurance
that the steps taken by SPSS to protect its proprietary rights will be adequate
to prevent misappropriation of its technology.

      Although SPSS software has never been the subject of an infringement
claim, there can be no assurance that third parties will not assert infringement
claims against SPSS in the future or that any infringement assertion will not
result in costly litigation or require SPSS to obtain a license to use the
intellectual property of third parties. There can be no assurance that these
licenses will be available on reasonable terms, or at all. There can also be no
assurance that competitors of SPSS will not independently develop technologies
that are substantially equivalent or superior to SPSS technologies.

               CERTAIN STOCKHOLDERS AND OFFICERS AND DIRECTORS MAY
                     CONTROL CORPORATE ACTIONS DUE TO THEIR
                             OWNERSHIP OF SPSS STOCK

      The executive officers and directors of SPSS beneficially own a
significant percentage of its outstanding shares of common stock, currently
estimated to be approximately 15.25%. As a result, the officers and directors
may be able to influence important corporate decisions that require stockholder
approval. The Norman H. Nie Revocable Trust Dated March 15, 1991 (a trust
beneficially controlled by Norman H. Nie, the chairman of our board of
directors) and affiliates of the Norman H. Nie Trust currently own approximately
4.51% of the outstanding shares of SPSS common stock. If the Norman H. Nie Trust
and affiliates of the Norman H. Nie Trust own in the aggregate at least 12.50%
of the outstanding shares of SPSS common stock, the Norman H. Nie Trust would be
entitled to nominate a director for inclusion in the management slate for
election to the Board of Directors of SPSS.

      Because of the combined voting power of the officers and directors of
SPSS, these individuals acting as a group may be able to influence its affairs
and business, including any determination with respect to a change in control of
SPSS, future issuances of SPSS common stock or other securities, declaration of
dividends on SPSS common stock and the election of directors. This influence
could have the effect of delaying, deferring or preventing a change of control
of SPSS which could deprive SPSS stockholders of the opportunity to sell their
shares of common stock at prices higher than prevailing market prices.

                      ANTI-TAKEOVER PROTECTIONS MAY MAKE IT
                   DIFFICULT FOR A THIRD PARTY TO ACQUIRE SPSS

      SPSS maintains a stockholder Rights Agreement which was adopted by the
Board in 1998 and amended in June 2004. The Rights Agreement and common stock
purchase rights issued in connection with the Right Agreement are intended to
ensure that the Company's stockholders receive fair and equal treatment in the
event of a proposed takeover of SPSS. The Rights Agreement may discourage a
potential acquirer from acquiring control of SPSS.

                                       7

<PAGE>

      The SPSS Certificate of Incorporation and By-Laws contain a number of
provisions, including provisions requiring an 80% super-majority stockholder
approval of specified actions and provisions for a classified Board of
Directors, which would make the acquisition of SPSS, by means of an unsolicited
tender offer, a proxy contest or otherwise, more difficult. The bylaws of SPSS
provide for a staggered board of directors so that only one-third of the total
number of directors are replaced or re-elected each year. Therefore, potential
acquirers of SPSS may face delays in replacing the existing directors.

      Senior executives and other officers of SPSS may be entitled to
substantial payments in the event of their termination without cause or
constructive termination following a change of control of SPSS. These payments
could have the effect of discouraging a potential acquirer from acquiring
control of SPSS.

                    SALES OF SPSS STOCK AVAILABLE FOR FUTURE
                    USE COULD DEPRESS THE STOCK PRICE OF SPSS

      In addition to the shares of common stock which are outstanding, as of May
31, 2005, there were vested options outstanding held by management to purchase
approximately 1,417,158 additional shares of common stock, with an average
exercise price of $19.62 per share, and unvested options to purchase
approximately 506,060 additional shares of common stock. SPSS has also
established a stock purchase plan available to employees of SPSS, which permits
participating SPSS employees to purchase shares of common stock at the end of
each specified six-month period at the lesser of 85% of the market price of the
common stock on the first day of the six-month period and 85% of the market
price of the common stock on the last day of the six-month period.

      No prediction can be made as to the effect, if any, that future sales, or
the availability of shares of SPSS common stock for future sales, will have on
the market price prevailing from time to time. Sales of substantial amounts of
common stock by SPSS or by stockholders who hold "restricted securities," or the
perception that these sales may occur, could adversely affect prevailing market
prices for the common stock.

                     THE COMPANY MAY NOT MAINTAIN EFFECTIVE
                    INTERNAL CONTROL OVER FINANCIAL REPORTING

      As described in the Company's Annual Report on Form 10-K for fiscal year
2004 filed with the Securities and Exchange Commission on March 16, 2005, as
amended by a Form 10-K/A filed with the Securities and Exchange Commission on
April 22, 2005 (collectively, the "2004 Annual Report"), both Management's
report on Internal Control over Financial Reporting and the Attestation Report
of the Registered Public Accounting Firm indicated that the Company did not
maintain effective internal control over financial reporting as of December 31,
2004 because of material weaknesses related to revenue and income taxes. While
the Company has taken steps to remedy these material weaknesses, if the
resulting actions are not effective, or if SPSS has additional material
weaknesses during subsequent fiscal years, our financial statements could be
inaccurate. If we have inaccurate financial statements, it could have a material
adverse effect on the value of SPSS common stock.

                                       8

<PAGE>

                                 USE OF PROCEEDS

      All of the shares of SPSS common stock being offered by means of this
reoffer prospectus will be sold by the selling stockholders, who will receive
all proceeds from any sales. SPSS will, however, receive proceeds from the
initial sale of these shares to participants in the Stock Purchase Plan. All
proceeds received as a result of the purchase of common stock by participants in
the Stock Purchase Plan will be used as working capital for the Company's
operations. In addition, other than the completion and filing of this
registration statement, SPSS will not participate in the reoffering or sale of
the shares of common stock by the selling stockholders.

                              SELLING STOCKHOLDERS

      When an affiliate stockholder notifies SPSS that he or she intends to sell
any shares of common stock purchased by him or her under the Stock Purchase
Plan, the Company intends to file a supplement to this reoffer prospectus to
identify the name of each selling stockholder and the number of shares of SPSS
common stock to be reoffered by that selling stockholder. Specifically, SPSS
will update the following table to identify information with respect to the
beneficial ownership of its common stock by each selling stockholder immediately
before the offering and as adjusted to reflect the sale of shares of SPSS common
stock under the reoffering. The selling stockholders identified in any
supplement to this reoffer prospectus may from time to time offer the shares of
common stock offered by means of this reoffer prospectus. The Company does not
know when or in what amounts the selling stockholders may offer shares for
resale and it cannot assure investors that the selling stockholders will sell
any or all of the shares offered by means of this reoffer prospectus.

<TABLE>
<CAPTION>
                                          Shares Beneficially               Number of Shares            Shares Beneficially
                                            Owned Before the                 Available for               Owned After the
Selling Stockholders                          Offering(1)                   Reoffer and Sale                Offering(2)
--------------------                      --------------------              ----------------            -------------------
                                           Number   Percentage                  Hereby                   Number  Percentage
                                           ------   ----------                  ------                   ------  ----------
<S>                                       <C>       <C>                     <C>                         <C>      <C>

</TABLE>

      (1)   SPSS will rely on information provided by the selling stockholders
            to determine the number of shares of its common stock which the
            selling stockholders will own as of a particular date before the
            offering.

      (2)   Assumes the sale of all shares that may be sold in the offering, and
            that no other shares beneficially owned by the selling stockholders
            are sold.

                                       9

<PAGE>

                              PLAN OF DISTRIBUTION

      The selling stockholders may, from time to time, sell all or a portion of
the shares covered by this reoffer prospectus by one or more of the following
methods:

      -     on the Nasdaq National Market, or such other exchange on which the
            SPSS common stock may from time to time be trading;

      -     in privately negotiated transactions or otherwise;

      -     at fixed prices that may be changed;

      -     at market prices prevailing at the time of the sale;

      -     at prices related to such market prices or at prices otherwise
            negotiated;

      -     in block trades in which the broker or dealer will attempt to sell
            the shares as agent but may position and resell a portion of the
            block as principal to facilitate the transaction;

      -     through purchases by a broker or dealer as principal;

      -     by an exchange distribution in accordance with the rules of such
            exchange;

      -     in ordinary brokerage transactions and transactions in which the
            broker solicits purchasers;

      -     through short sales; or

      -     by a combination of any of the above methods of sale.

      In effecting sales, brokers and dealers engaged by the selling
stockholders may arrange for other brokers or dealers to participate. Brokers or
dealers may receive commissions or discounts from the selling stockholders, or,
if any broker-dealer acts as agent for the purchaser of the shares, from the
purchaser, in amounts to be negotiated which are not expected to exceed those
customary in the types of transactions involved. Broker-dealers may agree with
the selling stockholders to sell a specified number of shares at a stipulated
price per share. To the extent a broker-dealer is unable to sell a specified
number of shares acting as agent for the selling stockholders, it will purchase
as principal any unsold shares at the price required to fulfill the
broker-dealer commitment to the selling stockholders. Broker-dealers who acquire
shares as principal may resell the shares from time to time in transactions that
may involve block transactions of the nature described above, in the
over-the-counter market, at prices and on terms then prevailing at the time of
sale, at prices related to the then-current market price or in negotiated
transactions. In connection with resales, broker-dealers may pay to or receive
from the purchasers of the shares commissions as described above.

      The selling stockholders may be deemed "underwriters" as defined in the
Securities Act of 1933 in connection with the sale of the shares offered by this
reoffer prospectus. Any broker-dealers or agents that participate with the
selling stockholders in sales of the shares may be considered to be
"underwriters" within the meaning of the Securities Act of 1933 in connection
with sales in which they

                                       10

<PAGE>

participate. If any broker-dealers or agents are considered to be
"underwriters," then any commissions they receive and any profit on the resale
of the shares purchased by them may be considered to be underwriting commissions
or discounts under the Securities Act of 1933.

      The selling stockholders and any other persons participating in the sale
or distribution of the shares will be subject to the Securities Exchange Act of
1934 and related rules and regulations, including Regulation M, to the extent it
applies. The Securities Exchange Act of 1934 and related rules may limit the
timing of purchases and sales of any of the shares by the selling stockholders,
or any other person, that may affect the marketability of the shares. The
selling stockholders also must comply with the applicable prospectus delivery
requirements under the Securities Act of 1933 in connection with the sale or
distribution of the shares.

      SPSS is required to pay certain fees and expenses incident to the
registration of the shares for resale by the selling stockholders.

      SPSS has agreed to indemnify the selling stockholders in certain
circumstances against certain liabilities, including liabilities under the
Securities Act of 1933. The selling stockholders have agreed to indemnify SPSS
in certain circumstances against certain liabilities, including liabilities
under the Securities Act of 1933.

      This offering will terminate on the date on which the selling stockholders
have sold all shares offered by means of this reoffer prospectus.

                                  LEGAL MATTERS

      The legality of the shares of our common stock being offered by means of
this reoffer prospectus has been passed on for SPSS by McGuireWoods LLP,
Chicago, Illinois.

                                     EXPERTS

      The consolidated financial statements and schedule of SPSS Inc. (the
Company) as of December 31, 2004 and 2003, and for each of the years in the
three-year period ended December 31, 2004, and management's assessment of the
effectiveness of internal control over financial reporting as of December 31,
2004 have been incorporated by reference herein and in the registration
statement in reliance upon the reports of KPMG LLP, independent registered
public accounting firm, incorporated by reference herein, and upon the authority
of said firm as experts in accounting and auditing.

      The audit report on management's assessment of the effectiveness of
internal control over financial reporting and the effectiveness of internal
control over financial reporting as of December 31, 2004, expresses the opinion
that the Company did not maintain effective internal control over financial
reporting as of December 31, 2004 because of the effect of the material
weaknesses on the achievement of the objectives of the control criteria and
contains explanatory paragraphs that state SPSS Inc. did not maintain effective
internal control over financial reporting as of December 31, 2004, because of
the effect of the material weaknesses identified in management's assessment
associated with the Company's accounting for revenue and income taxes.

                                       11

<PAGE>

                    WHERE INVESTORS CAN FIND MORE INFORMATION

      SPSS has filed a registration statement on Form S-8 with the SEC under the
Securities Act of 1933, to allow the selling stockholders to resell the common
stock offered by means of this reoffer prospectus. This reoffer prospectus,
which is a part of the registration statement, does not contain all of the
information identified in the registration statement. For further information
about the Company and the common stock offered by means of this reoffer
prospectus, please refer to the registration statement and the exhibits filed as
a part of the registration statement. Statements contained in this reoffer
prospectus as to the contents of any contract or other document filed as an
exhibit to the registration statement are not necessarily complete. If a
contract or document has been filed as an exhibit to the registration statement,
the Company refers investors to the copy of the contract or document that has
been filed.

      SPSS is subject to the information and periodic reporting requirements of
the Securities Exchange Act of 1934. In accordance with those requirements, SPSS
files annual, quarterly and special reports, proxy statements and other
information with the SEC. Investors can read and copy any document the Company
files at the SEC's public reference rooms at the following location:

                           Judiciary Plaza
                           450 Fifth Street, N.W.
                           Room 1024
                           Washington, D.C., 20549

      Investors can request copies of these documents upon payment of a
duplicating fee, by writing to the SEC. Please call the SEC at 1-800-SEC-0330
for further information on the operation of the public reference rooms and the
procedure for obtaining copies.

      The SEC maintains an Internet site that contains reports, proxy and
information statements, and other information regarding issuers that file
electronically with the SEC. The documents that SPSS files with the SEC,
including the registration statement, are available to investors on this web
site. Investors can log onto the SEC's web site at http://www.sec.gov. Certain
information is also available at the SPSS website at http://www.spss.com.

                      INFORMATION INCORPORATED BY REFERENCE

      The SEC allows SPSS to "incorporate by reference" the information that the
Company files with the SEC, which means that SPSS can disclose important
information to investors by referring to those documents. As a result, investors
may need to review other documents filed by SPSS with the SEC to obtain more
information. Information is incorporated into this reoffer prospectus in two
ways. First, if information is contained in a document that SPSS filed with the
SEC before the date of this reoffer prospectus, the document is specifically
identified below. Second, all of the information provided in a periodic or other
report or proxy statement filed by SPSS with the SEC after the date of this
reoffer prospectus and before the date that the offering described in this
reoffer prospectus is terminated is incorporated by reference.

      The information contained in the documents the Company incorporates by
reference is considered a part of this reoffer prospectus. Additionally, because
information concerning SPSS,

                                       12

<PAGE>

whether contained in this reoffer prospectus or in a document incorporated by
reference, will be amended or superseded by more current information contained
in later filed documents, the information that SPSS files with the SEC after the
date of this reoffer prospectus will update and supersede older information
contained in, or incorporated by reference into, this reoffer prospectus.

      SPSS incorporates by reference into this reoffer prospectus all the
documents listed below:

      -     The annual report of SPSS Inc. on Form 10-K filed with the SEC on
            March 16, 2005 for the fiscal year ended December 31, 2004, as
            amended by that certain Amendment No. 1 to Annual Report on Form
            10-K/A filed with the SEC on April 22, 2005.

      -     The quarterly report of SPSS Inc. on Form 10-Q filed with the SEC on
            May 6, 2005 for the fiscal quarter ended March 31, 2005.

      -     The current report of SPSS Inc. on form 8-K, dated June 15, 2005,
            filed with the SEC on June 15, 2005. The Form 8-K reported that
            the SPSS stockholders approved, and the Company adopted, the SPSS
            Inc. Employee Stock Purchase Plan.

      -     The current report of SPSS Inc. on Form 8-K, dated May 6, 2005,
            filed with the SEC on May 12, 2005. The Form 8-K reported that the
            SPSS Audit Committee dismissed KPMG LLP as the Company's independent
            auditors and engaged Grant Thornton LLP as the Company's independent
            auditors. The Form 8-K attached a letter from KPMG LLP to the SEC.

      -     The current report of SPSS Inc. on Form 8-K, dated May 4, 2004,
            filed with the SEC on May 6, 2005. The Form 8-K reported that SPSS
            had held its First Quarter 2005 Earnings Release Conference Call on
            May 4, 2004. The Form 8-K attached a transcript of the conference
            call as an exhibit.

      -     The current report of SPSS Inc. on Form 8-K, dated May 3, 2005,
            filed with the SEC on May 4, 2005. The Form 8-K reported that SPSS
            had issued a press release announcing its results for the fiscal
            quarter ended March 31, 2005 and attached a copy of the press
            release as an exhibit.

      -     The current report of SPSS Inc. on Form 8-K, dated April 28, 2005,
            filed with the SEC on May 2, 2005. The Form 8-K reported that the
            Company amended and restated the change of control agreements that
            it maintains with certain executive officers, and the Company
            entered into new change of control agreements with additional
            officers.

      -     The current report of SPSS Inc. on Form 8-K, dated April 28, 2005,
            filed with the SEC on April 28, 2005. The Form 8-K reported that the
            Company's Board of Directors ratified an amendment to the SPSS Inc.
            Code of Business Conduct and Ethics to modify the procedure by which
            questions or concerns regarding the Company's accounting methods,
            internal accounting controls, auditing matters or procedures for
            reporting financial information may be reported to the Audit
            Committee of the Board of Directors.

                                       13

<PAGE>

      -     The current report of SPSS Inc. on Form 8-K, dated April 28, 2005,
            filed with the SEC on April 28, 2005. The Form 8-K reported that the
            Company's Board of Directors had set annual base salaries and bonus
            targets for the Company's senior executive officers.

      -     The current report of SPSS Inc. in Form 8-K, dated March 14, 2005,
            filed with the SEC on March 14, 2005. The Form 8-K reported that the
            Company amended and restated its employment agreement with Mr.
            Raymond Panza, the Company's Executive Vice President, Corporate
            Operations, Chief Financial Officer and Secretary.

      -     The current report of SPSS Inc. in Form 8-K, dated March 14, 2005,
            filed with the SEC on March 14, 2005. The Form 8-K reported that the
            Company amended and restated its employment agreement with Mr. Jack
            Noonan, the Company's President and Chief Executive Officer.

      -     The current report of SPSS Inc. in Form 8-K, dated February 16,
            2005, filed with the SEC on February 18, 2005. The Form 8-K reported
            that SPSS had held its Fourth Quarter and Fiscal Year 2004 Earnings
            Release Conference Call on February 16, 2005. The Form 8-K attached
            a transcript of the conference call as an exhibit.

      -     The current report of SPSS Inc. in Form 8-K, dated February 15,
            2005, filed with the SEC on February 16, 2005. The Form 8-K reported
            that SPSS had issued a press release announcing its results for the
            fiscal quarter ended December 31, 2004 and for fiscal year 2004 and
            attached a copy of the press release as an exhibit.

      -     The proxy statement, filed with the SEC on May 16, 2005, for the
            SPSS annual meeting of stockholders held on June 15, 2005, except
            for the compensation committee report contained therein.

      -     The description of the common stock of SPSS Inc. contained in its
            registration statement filed with the SEC on a Form 8-A dated August
            4, 1993, as amended by the Form 8-A12G/A dated August 31, 2004,
            pursuant to Section 12 of the Securities Exchange Act of 1934.

      In addition to the documents listed above, SPSS incorporates by reference
into this reoffer prospectus all documents filed by SPSS with the SEC under
Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as
amended, after the date of this reoffer prospectus and until all shares of the
common stock being offered by means of this reoffer prospectus have been sold by
the selling stockholders or the registration statement which SPSS has filed with
the SEC relating to the common stock ceases to be effective.

      SPSS will deliver a free copy of any document incorporated by reference
into this reoffer prospectus but not delivered with this reoffer prospectus to
anyone who receives this reoffer prospectus. Exhibits filed with the documents
that are incorporated by reference into this reoffer prospectus will be
delivered only if the exhibits have been specifically incorporated by reference.
Requests for any of these documents may be made in writing or orally and should
be directed to: Chief Financial Officer, SPSS Inc., 233 South Wacker Drive, 11th
Floor, Chicago, Illinois 60606, (312) 651-3000.

                                       14

<PAGE>

      No dealer, salesperson, or any other person has been authorized to give
any information or to make any representation not contained in this reoffer
prospectus. Any information or representation not contained herein must not be
relied upon as having been authorized by SPSS or any selling stockholder. This
reoffer prospectus does not constitute an offer to sell, or a solicitation of an
offer to buy, any securities other than the securities covered by this reoffer
prospectus; nor does it constitute an offer to sell, or a solicitation of an
offer to buy, any of the securities covered by this reoffer prospectus by SPSS
or any selling stockholder in any state where such offer or solicitation is not
permitted. Neither the delivery of this reoffer prospectus nor any sale made
hereunder shall, under any circumstances, create an implication that there has
been no change in the affairs of SPSS since the date on the front of this
document.

      All selling stockholders that effect transactions in the shares of common
stock offered by means of this prospectus are required to deliver a copy of
their prospectus to any purchaser of the shares of common stock at or before the
time a certificate representing the shares of common stock is delivered to the
purchaser.

                                       15

<PAGE>

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item  3. Incorporation of Certain Documents by Reference

      The SEC allows SPSS to "incorporate by reference" the information that the
Company files with the SEC, which means that SPSS can disclose important
information to investors by referring to those documents. As a result, investors
may need to review other documents filed by SPSS with the SEC to obtain more
information. The information contained in the documents SPSS incorporates by
reference is considered a part of this registration statement. Additionally,
because information concerning SPSS, whether contained in this registration
statement or in a document incorporated by reference, will be amended or
superseded by more current information contained in later filed documents, the
information that SPSS files with the SEC after the date of this registration
statement, and before the filing of a post-effective amendment to this
registration statement which indicates that all securities offered by this
registration statement have been sold or which deregisters all securities
remaining unsold, will update and supersede older information contained in, or
incorporated by reference into, this registration statement.

      SPSS hereby incorporates by reference the following documents previously
filed with the SEC:

            (a)   The annual report of SPSS Inc. on Form 10-K filed with the SEC
                  on March 16, 2005 for the fiscal year ended December 31, 2004,
                  as amended by that certain Amendment No. 1 to Annual Report on
                  Form 10-K/A filed with the SEC on April 22, 2005.

            (b)   The quarterly report of SPSS Inc. on Form 10-Q filed with the
                  SEC on May 6, 2005 for the fiscal quarter ended March 31,
                  2005.

            (c)   The current report of SPSS Inc. on form 8-K, dated June 15,
                  2005, filed with the SEC on June 15, 2005. The Form 8-K
                  reported that the SPSS stockholders approved, and the Company
                  adopted, the SPSS Inc. Employee Stock Purchase Plan.

            (d)   The current report of SPSS Inc. on Form 8-K, dated May 6,
                  2005, filed with the SEC on May 12, 2005. The Form 8-K
                  reported that the SPSS Audit Committee dismissed KPMG LLP as
                  the Company's independent auditors and engaged Grant Thornton
                  LLP as the Company's independent auditors. The Form 8-K
                  attached a letter from KPMG LLP to the SEC.

            (e)   The current report of SPSS Inc. on Form 8-K, dated May 4,
                  2004, filed with the SEC on May 6, 2005. The Form 8-K reported
                  that SPSS had held its First Quarter 2005 Earnings Release
                  Conference Call on May 4, 2004. The Form 8-K attached a
                  transcript of the conference call as an exhibit.

            (f)   The current report of SPSS Inc. on Form 8-K, dated May 3,
                  2005, filed with the SEC on May 4, 2005. The Form 8-K reported
                  that SPSS had issued a press release

                                      II-1

<PAGE>

                  announcing its results for the fiscal quarter ended March 31,
                  2005 and attached a copy of the press release as an exhibit.

            (g)   The current report of SPSS Inc. on Form 8-K, dated April 28,
                  2005, filed with the SEC on May 2, 2005. The Form 8-K reported
                  that the Company amended and restated the change of control
                  agreements that it maintains with certain executive officers,
                  and the Company entered into new change of control agreements
                  with additional officers.

            (h)   The current report of SPSS Inc. on Form 8-K, dated April 28,
                  2005, filed with the SEC on April 28, 2005. The Form 8-K
                  reported that the Company's Board of Directors ratified an
                  amendment to the SPSS Inc. Code of Business Conduct and Ethics
                  to modify the procedure by which questions or concerns
                  regarding the Company's accounting methods, internal
                  accounting controls, auditing matters or procedures for
                  reporting financial information may be reported to the Audit
                  Committee of the Board of Directors.

            (i)   The current report of SPSS Inc. on Form 8-K, dated April 28,
                  2005, filed with the SEC on April 28, 2005. The Form 8-K
                  reported that the Company's Board of Directors had set annual
                  base salaries and bonus targets for the Company's senior
                  executive officers.

            (j)   The current report of SPSS Inc. in Form 8-K, dated March 14,
                  2005, filed with the SEC on March 14, 2005. The Form 8-K
                  reported that the Company amended and restated its employment
                  agreement with Mr. Raymond Panza, the Company's Executive Vice
                  President, Corporate Operations, Chief Financial Officer and
                  Secretary.

            (k)   The current report of SPSS Inc. in Form 8-K, dated March 14,
                  2005, filed with the SEC on March 14, 2005. The Form 8-K
                  reported that the Company amended and restated its employment
                  agreement with Mr. Jack Noonan, the Company's President and
                  Chief Executive Officer.

            (l)   The current report of SPSS Inc. in Form 8-K, dated February
                  16, 2005, filed with the SEC on February 18, 2005. The Form
                  8-K reported that SPSS had held its Fourth Quarter and Fiscal
                  Year 2004 Earnings Release Conference Call on February 16,
                  2005. The Form 8-K attached a transcript of the conference
                  call as an exhibit.

            (m)   The current report of SPSS Inc. in Form 8-K, dated February
                  15, 2005, filed with the SEC on February 16, 2005. The Form
                  8-K reported that SPSS had issued a press release announcing
                  its results for the fiscal quarter ended December 31, 2004 and
                  for fiscal year 2004 and attached a copy of the press release
                  as an exhibit.

            (n)   The proxy statement, filed with the SEC on May 16, 2005, for
                  the SPSS annual meeting of stockholders held on June 15, 2005,
                  except for the compensation committee report contained
                  therein.

                                      II-2

<PAGE>

            (o)   The description of the common stock of SPSS Inc. contained in
                  its registration statement filed with the SEC on a Form 8-A
                  dated August 4, 1993, as amended by the Form 8-A12G/A dated
                  August 31, 2004, pursuant to Section 12 of the Securities
                  Exchange Act of 1934.

      In addition to the documents listed above, SPSS incorporates by reference
into this registration statement all documents filed by SPSS with the SEC under
Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934 after
the date of this registration statement and prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all securities then remaining unsold.

Item  4. Description of Securities

            Not applicable.

Item  5. Interests of Named Experts and Counsel

            Not applicable.

Item  6. Indemnification of Officers and Directors

      The SPSS Certificate of Incorporation provides for indemnification to the
full extent permitted by the laws of the State of Delaware against, and with
respect to, threatened, pending or completed actions, suits or proceedings
arising from, or alleged to arise from, a party's actions or omissions as a
director, officer, employee or agent of SPSS or of any other corporation,
partnership, joint venture, trust or other enterprise which has served in such
capacity at the request of SPSS if the acts or omissions occurred, or were or
alleged to have occurred, while such party was a director or officer of SPSS.
Generally, under Delaware law, indemnification will only be available where an
officer or director can establish that he or she acted in good faith and in a
manner which was reasonably believed to be in, or not opposed to, the best
interests of SPSS.

      Section 145 of the Delaware General Corporation Law provides that a
corporation may indemnify any person made a party to an action, suit or
proceeding (other than an action by, or in the right of, the corporation) by
reason of the fact that the person is or was a director, officer, employee or
agent of the corporation, or is or was serving at the request of the
corporation, against expenses (including attorneys' fees), judgments, fines and
amounts paid in settlement actually and reasonably incurred by such person in
connection with such action, suit or proceeding, if such person acted in good
faith and in a manner such person reasonably believed to be in, or not opposed
to, the best interests of the corporation, and, with respect to any criminal
action or proceeding, had no reasonable cause to believe such person's conduct
was unlawful.

      In addition, Section 145 provides that a corporation may indemnify any
person made a party to an action, suit or proceeding by or in the right of the
corporation to procure a judgment in its favor by reason of the fact that the
person is or was a director, officer, employee or agent of

                                      II-3

<PAGE>

the corporation, or is or was serving at the request of the corporation, against
expenses (including attorneys' fees) actually and reasonably incurred by such
person in connection with the defense or settlement of such action or suit if
such person acted in good faith and in a manner such person reasonably believed
to be in, or not opposed to, the best interests of the corporation and except
that no indemnification shall be made in respect of any claim, issue or matter
as to which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Delaware Court of Chancery or the court
in which such action or suit was brought shall determine upon application that,
despite the adjudication of liability but in view of all the circumstances of
the case, such person is fairly and reasonably entitled to indemnity for such
expenses which the court shall deem proper.

      Section 145 also provides that to the extent a director, officer, employee
or agent of a corporation has been successful on the merits or otherwise in
defense of any action, suit or proceeding referred to above, or defense of any
claim, issue or matter therein, he or she shall be indemnified against expenses
(including attorneys' fees) actually and reasonable incurred in connection
therewith.

      Under the applicable provisions of the Delaware General Corporation Law,
any indemnification described above shall be made by the corporation only as
authorized in the specific case upon a determination that the indemnification of
the director, officer, employee or agent is proper under the circumstances
because he or she has met the applicable standard of conduct. Such determination
shall be made:

      (1)   by the Board of Directors by a majority vote of directors who are
            not parties to such action, suit or proceeding, even though less
            than a quorum; or

      (2)   by a committee of directors who are not parties to the action, suit
            or proceeding, as designated by a majority vote of such directors,
            even though less than a quorum; or

      (3)   if no directors who are not parties to the action, suit, or
            proceeding exist, or if such directors so direct, by independent
            legal counsel in a written opinion; or

      (4)   by the affirmative vote of a majority of the shares entitled to vote
            thereon.

Item  7. Exemption from Registration Claimed.

            Not applicable.

Item  8. Exhibits.

<TABLE>
<CAPTION>
Exhibit                                                                                                        Incorporation
 Number       Description                                                                                       by Reference
-------       -----------                                                                                      -------------
<S>           <C>                                                                                              <C>
   5.1        Opinion of McGuireWoods LLP regarding legality of shares of Common Stock.
</TABLE>

                                      II-4

<PAGE>

<TABLE>
<S>          <C>                                                                                                       <C>
10.55        SPSS Inc. Employee Stock Purchase Plan.                                                                   (1)
 23.1        Consent of KPMG LLP.
 23.2        Consent of McGuireWoods LLP (contained in opinion filed as Exhibit 5.1).
 24.1        Power of Attorney (contained within the signature page to the Registration Statement on Form S-8).        (2)
</TABLE>

(1)   Previously filed with the Report on Form 8-K of SPSS Inc., dated June 15,
      2005 filed on June 15, 2005. (File No. 000-22194)

(2)   Power of attorney is contained within the signature page.

Item  9. Undertakings.

      (a) The undersigned registrant hereby undertakes:

            (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement:

                  To include any material information with respect to the plan
      of distribution not previously disclosed in this registration statement or
      any material change to such information in the registration statement.

            (2) That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

            (3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

      (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Securities Exchange Act of
1934) that is incorporated by reference in the registration statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.

      (c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the registrant pursuant to the foregoing provisions, or otherwise,
the registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Securities Act of 1933 and is, therefore, unenforceable. In the event
that a claim for indemnification against such liabilities (other than the
payment by the registrant of expenses

                                      II-5

<PAGE>

incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act of 1933 and will be governed by the
final adjudication of such issue.

                                      II-6

<PAGE>

                                   SIGNATURES

      Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Chicago, State of Illinois, on June 15, 2005.

                                      SPSS Inc.

                                      By: /s/ Jack Noonan
                                          -------------------------------------
                                          Jack Noonan
                                          President and Chief Executive Officer

                                POWER OF ATTORNEY

      Each person whose signature appears below hereby constitutes and appoints
Jack Noonan and Raymond H. Panza, and each of them, the true and lawful
attorneys-in-fact and agents of the undersigned, with full power of substitution
and resubstitution, for and in the name, place and stead of the undersigned, in
any and all capacities, to sign any and all amendments (including post-effective
amendments) to this registration statement, and to file the same, with all
exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, and hereby grants to such attorneys-in-fact
and agents, and each of them, full power and authority to do and perform each
and every act and thing requisite and necessary to be done in furtherance of the
foregoing, as fully to all intents and purposes as the undersigned might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or any of them, or their or his substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

      Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities indicated on June 15, 2005.

<TABLE>
<CAPTION>
Signature                                  Title(s)
---------                                  --------
<S>                            <C>
/s/ Norman H. Nie              Chairman of the Board of Directors
--------------------
Norman H. Nie

/s/ Jack Noonan                President, Chief Executive Officer and Director
--------------------
Jack Noonan

/s/ Raymond H. Panza           Executive Vice President, Corporate Operations,
--------------------           Chief Financial Officer and Secretary
Raymond H. Panza
</TABLE>

                                      II-7

<PAGE>

<TABLE>
<S>                            <C>
/s/ Marc D. Nelson             Corporate Controller
---------------------------
Marc D. Nelson

/s/ Michael Blair              Director
---------------------------
Michael Blair

/s/ Charles R. Whitchurch      Director
---------------------------
Charles R. Whitchurch

/s/ Merritt Lutz               Director
---------------------------
Merritt Lutz

/s/ Promod Haque               Director
---------------------------
Promod Haque

/s/ William Binch              Director
---------------------------
William Binch

/s/ Kenneth Holec              Director
---------------------------
Kenneth Holec
</TABLE>

                                      II-8

<PAGE>

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                               EXHIBITS FILED WITH

                                    FORM S-8

                             REGISTRATION STATEMENT

                                      UNDER

                           THE SECURITIES ACT OF 1933

                                    SPSS INC.

<PAGE>

                                    SPSS INC.

                                  EXHIBIT INDEX
<TABLE>
<CAPTION>
Exhibit
  No.         Description
-------       -----------
<S>           <C>
   5.1        Opinion of McGuireWoods LLP regarding legality of shares of Common Stock.
 10.55        SPSS Inc. Employee Stock Purchase Plan.(1)
  23.1        Consent of KPMG LLP.
  23.2        Consent of McGuireWoods LLP (contained in opinion filed as Exhibit 5.1).
  24.1        Power of Attorney (contained within the signature page to the Registration Statement on Form S-8).
</TABLE>

(1)   Previously filed with the Report on Form 8-K of SPSS Inc., dated June 15,
      2005 filed on June 15, 2005. (File No. 000-22194)

                                       2
[{"type": "S-8", "sequence": "1", "filename": "c95948sv8.txt", "description": "REGISTRATION STATEMENT", "secsgml_size_bytes": 80099}]
{"company-data": {"conformed-name": "SPSS INC", "cik": "0000869570", "assigned-sic": "7372", "irs-number": "362815480", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-125824", "film-number": "05897332"}, "business-address": {"street1": "233 S WACKER DR", "city": "CHICAGO", "state": "IL", "zip": "60606", "phone": "3123292400"}, "mail-address": {"street1": "233 SOUTH WACKER DRIVE", "city": "CHICAGO", "state": "IL", "zip": "60606"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 15, 2005

                                                      REGISTRATION NO. 333-_____
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                       ----------------------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                                    SPSS INC.
              ----------------------------------------------------
             (Exact name of Registrant as specified in its charter)

              DELAWARE                                36-2815480
   -------------------------------                ------------------
   (State or other jurisdiction of                 (I.R.S. Employer
   incorporation or organization)                 Identification No.)

                             233 SOUTH WACKER DRIVE
                             CHICAGO, ILLINOIS 60606
                                 (312) 651-3000
   --------------------------------------------------------------------------
  (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF
                   REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)

                                    SPSS INC.
                          EMPLOYEE STOCK PURCHASE PLAN

                                RAYMOND H. PANZA
                 EXECUTIVE VICE PRESIDENT, CORPORATE OPERATIONS,
                      CHIEF FINANCIAL OFFICER AND SECRETARY
                                    SPSS Inc.
                             233 South Wacker Drive
                                   11th Floor
                             Chicago, Illinois 60606
                                 (312) 651-3000
             --------------------------------------------------------
            (Name, address, including zip code, and telephone number,
                   including area, code, of agent for service)

                                   Copies to:

                            Lawrence R. Samuels, Esq.
                                McGuireWoods LLP
                              77 West Wacker Drive
                                   Suite 4100
                             Chicago, Illinois 60601
                                 (312) 849-8100

                         CALCULATION OF REGISTRATION FEE
Proposed
                                        Amount               maximum                Proposed               Amount of
          Title of                       to be            offering price           aggregate              registration
 Securities to be registered         registered(1)         per share(2)        offering price(3)              fee
 ----------------------------        ------------         --------------       ----------------           ------------
Common Stock, $0.01 par value           500,000               $18.05              $9,025,000               $1,062.24
                                        =======               ======              ==========               =========
(1) The securities being registered include a maximum of 500,000 shares
issuable pursuant to the SPSS Inc. Employee Stock Purchase Plan assuming full
participation of employees under that plan.

      (2) Solely for the purpose of calculating the registration fee, the
offering price per share, the aggregate offering price and the amount of the
registration fee have been computed in accordance with Rule 457(c) under the
Securities Act of 1933. Accordingly, the price per share of common stock has
been calculated to be equal to the average of the high and low prices for a
share of common stock as reported by the NASDAQ National Market on June 10,
2005, which is a specified date within five business days prior to the original
date of filing of this Registration Statement.

      (3) Solely for the purpose of calculating the registration fee, the
proposed aggregate offering price has been estimated in accordance with Rule
457(h) promulgated under the Securities Act of 1933.
EXPLANATORY NOTE

This registration statement registers:

      -     Shares of common stock that may be issued upon the purchase of
            shares pursuant to the SPSS Inc. Employee Stock Purchase Plan
            (referred to as the "Stock Purchase Plan");

      -     Certain resales of shares of common stock that may be issued upon
            the purchase of shares pursuant to the Stock Purchase Plan.

      This registration statement contains two parts. The first part contains a
reoffer prospectus prepared in accordance with Part I of Form S-3, pursuant to
General Instruction C to Form S-8. The reoffer prospectus may be used for
reoffers or resales of the shares that have been acquired by the selling
stockholders. The second part contains information required in the registration
statement under Part II of Form S-8.

      The information specified by Part I of Form S-8 is not being filed with
the Securities and Exchange Commission as permitted by the Note in Part I of
Form S-8. This information will be sent or given to the participants in the
Stock Purchase Plan as specified by Rule 428(b)(1) under the Securities Act of
1933.
REOFFER PROSPECTUS

                                    SPSS INC.

                                  Common Stock

      This reoffer prospectus relates to an offering of shares of common stock
of SPSS Inc. (referred to as "SPSS" or the "Company") which may be issued upon
the purchase of shares by certain selling stockholders pursuant to the SPSS Inc.
Employee Stock Purchase Plan (referred to as the "Stock Purchase Plan").

      The common stock being registered may be offered for the account of the
stockholders, who may from time to time be identified under the section heading
"SELLING STOCKHOLDERS" in a supplement to this reoffer prospectus. The selling
stockholders will receive all of the proceeds from any sales of the shares of
SPSS common stock offered under this reoffer prospectus. Although SPSS will not
receive any proceeds from the selling stockholders' sale of shares of the
Company's common stock offered under this reoffer prospectus, SPSS will receive
proceeds from the initial cash purchase of its common stock by the selling
stockholders under the Stock Purchase Plan. All proceeds received as a result of
the purchase of SPSS common stock under the Stock Purchase Plan will be used as
working capital for the Company's operations.

      The shares of SPSS common stock issued to the selling stockholders are
being registered to permit the selling stockholders to sell the shares from time
to time in the public market. The selling stockholders may sell the shares of
SPSS common stock on the Nasdaq National Market, in negotiated transactions, or
through a combination of these methods, at prevailing market prices or at
privately negotiated prices, either directly or through agents or
broker-dealers, or through any other means described in the section titled "PLAN
OF DISTRIBUTION," beginning on Page 10.

      The Company's common stock is quoted on the Nasdaq National Market under
the symbol "SPSS." On June 14, 2005, the last reported sale price of SPSS common
stock on the Nasdaq National Market was $18.48 per share. Our address is
233 South Wacker Drive, 11th Floor, Chicago, Illinois 60606 and our phone number
is (312) 651-3000.

      The shares offered by means of this reoffer prospectus involve a high
degree of risk. Eligible persons should participate in the Stock Purchase Plan
and purchase shares of SPSS common stock only if they can afford a loss of all
or a portion of the investment in those shares. SEE "RISK FACTORS" BEGINNING ON
PAGE 2.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THE COMMON STOCK TO WHICH THIS REOFFER
PROSPECTUS RELATES OR PASSED UPON THE ADEQUACY OR ACCURACY OF THIS REOFFER
PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

              The date of this reoffer prospectus is June 15, 2005.
TABLE OF CONTENTS
Page
                                                                ----
FORWARD-LOOKING STATEMENTS.................................       1

RISK FACTORS...............................................       2

USE OF PROCEEDS............................................       9

SELLING STOCKHOLDERS.......................................       9

PLAN OF DISTRIBUTION.......................................      10

LEGAL MATTERS..............................................      11

EXPERTS....................................................      11

WHERE INVESTORS CAN FIND MORE INFORMATION..................      12

INFORMATION INCORPORATED BY REFERENCE......................      12
i
FORWARD-LOOKING STATEMENTS

      THIS REOFFER PROSPECTUS CONTAINS FORWARD-LOOKING STATEMENTS WITHIN THE
MEANING OF SECTION 27A OF THE SECURITIES ACT OF 1933 AND SECTION 21E OF THE
SECURITIES EXCHANGE ACT OF 1934. SPSS MAY ALSO MAKE WRITTEN FORWARD-LOOKING
STATEMENTS IN ITS PERIODIC REPORTS TO THE SECURITIES AND EXCHANGE COMMISSION, IN
ITS PRESS RELEASES AND OTHER WRITTEN MATERIALS AND IN ORAL STATEMENTS MADE BY
ITS OFFICERS, DIRECTORS OR EMPLOYEES TO THIRD PARTIES. STATEMENTS THAT ARE NOT
HISTORICAL FACTS, INCLUDING, WITHOUT LIMITATION, STATEMENTS REGARDING THE
COMPANY'S EXPECTATIONS, BELIEFS, INTENTIONS OR FUTURE STRATEGIES, ARE
FORWARD-LOOKING STATEMENTS. THESE STATEMENTS ARE BASED ON THE BELIEFS AND
ASSUMPTIONS OF SPSS MANAGEMENT AND ON INFORMATION CURRENTLY AVAILABLE TO THE
COMPANY. FORWARD-LOOKING STATEMENTS INCLUDE STATEMENTS PRECEDED BY, FOLLOWED BY
OR THAT INCLUDE THE WORDS "EXPECTS," "ANTICIPATES," "INTENDS," "BELIEVES,"
"PLANS," "ESTIMATES," "DESIGNED," "MAY," COULD," "PREDICTS" OR SIMILAR LANGUAGE.

      ALL FORWARD-LOOKING STATEMENTS INCLUDED IN THIS DOCUMENT ARE BASED ON
INFORMATION AVAILABLE TO SPSS ON THE DATE HEREOF. THE COMPANY CAUTIONS INVESTORS
THAT ITS BUSINESS AND FINANCIAL PERFORMANCE AND THE MATTERS DESCRIBED IN THESE
FORWARD-LOOKING STATEMENTS ARE SUBJECT TO SUBSTANTIAL RISKS AND UNCERTAINTIES.
THE COMPANY'S FUTURE RESULTS MAY DIFFER MATERIALLY FROM THOSE EXPRESSED IN THE
FORWARD-LOOKING STATEMENTS CONTAINED IN THIS REOFFER PROSPECTUS AND IN THE
INFORMATION INCORPORATED BY REFERENCE IN THIS REOFFER PROSPECTUS (SEE "WHERE YOU
CAN FIND MORE INFORMATION"). A NUMBER OF IMPORTANT FACTORS COULD CAUSE ACTUAL
RESULTS TO DIFFER MATERIALLY FROM THOSE CONTAINED IN ANY FORWARD-LOOKING
STATEMENT. SPECIFIC FACTORS THAT MIGHT CAUSE THESE DIFFERENCES ARE DISCUSSED
THROUGHOUT THIS REOFFER PROSPECTUS, INCLUDING IN THE SECTION ENTITLED "RISK
FACTORS." IN ADDITION, FOR FURTHER INFORMATION REGARDING THESE RISKS AND
UNCERTAINTIES, PLEASE REFER TO PUBLICLY AVAILABLE DOCUMENTS THAT SPSS HAS FILED
WITH THE SECURITIES AND EXCHANGE COMMISSION.

      BECAUSE OF THESE RISKS AND UNCERTAINTIES, SOME OF WHICH MAY NOT BE
CURRENTLY ASCERTAINABLE AND MANY OF WHICH ARE BEYOND THE COMPANY'S CONTROL,
ACTUAL RESULTS COULD DIFFER MATERIALLY FROM THOSE PROJECTED IN THE
FORWARD-LOOKING STATEMENTS. DEVIATIONS BETWEEN ACTUAL FUTURE EVENTS AND THE
COMPANY'S ESTIMATES AND ASSUMPTIONS COULD LEAD TO RESULTS THAT ARE MATERIALLY
DIFFERENT FROM THOSE EXPRESSED IN OR IMPLIED BY THE FORWARD LOOKING STATEMENTS.
SPSS DOES NOT INTEND TO UPDATE THESE FORWARD LOOKING STATEMENTS TO REFLECT
ACTUAL FUTURE EVENTS.

                                       1
RISK FACTORS

      Potential investors should carefully consider the risks described below
before making an investment decision. The risks and uncertainties described
below are not the only ones facing SPSS. Additional risks and uncertainties not
presently known to SPSS, or those it currently believes are immaterial, could
also impair its business operations. If any of the following risks actually
occurred, the business and financial conditions of SPSS or the results of its
operations could be materially adversely affected, the trading price of SPSS
common stock could decline, and investors could lose all or part of their
investment in the Company.

               THE COMPANY'S FINANCIAL RESULTS AND STOCK PRICE MAY
                      BE AFFECTED BY QUARTERLY FLUCTUATIONS

      The quarterly revenue and operating results of SPSS have varied in the
past and may continue to do so in the future. Future revenues and operating
results will depend upon, among other factors:

      -     the number and timing of product updates and new product
            introductions;

      -     delays in product development and introduction;

      -     purchasing schedules of the Company's customers;

      -     changes in foreign currency exchange rates;

      -     changes in prescribed accounting rules and practices;

      -     product and market development expenditures;

      -     the timing of product shipments;

      -     changes in the Company's product mix;

      -     timing, costs and effects of acquisitions; and

      -     general economic conditions.

      Because expense levels are to a large extent based on its forecasts of
future revenues, the Company's operating results may be adversely affected if
our future revenues fall below expectations. Accordingly, SPSS believes that
quarter-to-quarter comparisons of its results of operations may not be
meaningful and should not be relied upon as an indication of future performance.

      SPSS has historically operated with very little backlog because its
products are generally shipped as orders are received. As a result, revenues in
any quarter are dependent on orders shipped and licenses renewed in that
quarter. SPSS has experienced a seasonal pattern in its operating results, with
the fourth quarter typically having the highest operating income.

      In addition, the timing and amount of the Company's revenues may be
affected by a number of factors that make estimation of operating results before
the end of a quarter uncertain. A significant portion of the Company's operating
expenses are relatively fixed, and planned expenditures are based primarily on
revenue forecasts. The variable profit margins on modest increases in sales
volume at the end of fiscal quarters are significant and, should SPSS fail to
achieve these revenue increases, net income could be materially affected.
Generally, if revenues do not meet its expectations in any given quarter, the
Company's operating results will be adversely affected. There can be no
assurance that profitability on a quarterly or annual basis can be achieved or
sustained in the future.

                                       2
THE ANTICIPATED BENEFITS OF THE COMPANY'S
                        ACQUISITIONS MAY NOT MATERIALIZE

      In recent years, SPSS has made a significant number of acquisitions,
including the acquisition of businesses based outside of the United States. Part
of the Company's growth strategy includes pursuing additional acquisitions. Any
of these transactions could be material to the Company's financial condition and
results of operations. In addition, the process of integrating an acquired
company, business or technology involves risk and may create unforeseen
operating difficulties and expenditures. These areas of risk include:

      -     the need to implement or remediate controls, procedures and policies
            at companies that, prior to the acquisition, lacked these controls,
            procedures and policies;

      -     interruption of, or a distraction of management's attention from,
            the Company's business;

      -     cultural challenges associated with integrating employees from the
            acquired company into the SPSS organization; and

      -     the need to integrate each company's accounting, management
            information, human resource and other administrative systems to
            permit effective management.

      Foreign acquisitions involve unique risks in addition to those mentioned
above, including those related to the integration of operations across different
cultures and languages, currency risks and the particular economic, political
and regulatory risks associated with specific countries.

      We may not be able to consummate these potential future acquisitions on
terms acceptable to us, or at all. Further, the anticipated benefit of many of
our acquisitions may not materialize. Future acquisitions or dispositions could
result in potentially dilutive issuances of our equity securities, the
incurrence of debt, contingent liabilities or amortization expenses, or
write-offs of goodwill, any of which could harm our financial condition. Any of
these events could have a material adverse effect on SPSS.

                       SPSS MAY NOT RESPOND ADEQUATELY TO
                           RAPID TECHNOLOGICAL CHANGES

      The computer software industry is characterized by rapid technological
advances, changes in customer requirements, as well as frequent enhancements to
and introductions of technologies. The future success of SPSS will depend upon
its ability to enhance its existing software and introduce new software products
that keep pace with technological developments, respond to evolving customer
requirements and achieve market acceptance. In particular, SPSS believes it must
continue to respond quickly to users' needs for greater functionality, improved
usability and support for new hardware and operating systems. Any failure by
SPSS to respond adequately to technological developments and customer
requirements, or any significant delays in software development or introduction,
could result in loss of revenues.

      In the past, SPSS has, on occasion, experienced delays in the introduction
of new software and enhancements to existing technology, primarily due to
difficulties with particular operating environments and problems with software
provided by third parties. The extent of these delays has varied depending upon
the size and scope of the project and the nature of the problems encountered.
These delays have most often resulted from "bugs" encountered in working with
new versions of

                                       3
operating systems and other third party software, and "bugs" or unexpected
difficulties in existing third party software which complicate integration with
SPSS software. From time to time, SPSS has discovered "bugs" in its software
that are resolved through maintenance releases or through periodic updates
depending upon the seriousness of the defect. There can be no assurance that
SPSS will be successful in developing and marketing new software or enhancements
to existing technology on a timely basis or that SPSS will not experience
significant delays or defects in its software in the future, which could have a
material adverse effect on SPSS. In addition, there can be no assurance that new
software or enhancements to existing technology developed by SPSS will achieve
market acceptance or that developments by others will not render SPSS
technologies obsolete or noncompetitive.

                     SPSS MAY FACE BUSINESS DECLINES DUE TO
                          OUR INTERNATIONAL OPERATIONS

      Revenues from operations outside of North America accounted for
approximately 49% of the Company's total revenues in 2002, 51% in 2003, and 55%
in 2004. SPSS expects that revenues from international operations will continue
to represent a large percentage of its net revenues and that this percentage may
increase, particularly as SPSS further "localizes" products by translating them
into additional languages and expands its operations through acquisitions of
companies outside the United States. A number of risk factors may affect the
Company's international revenues, including:

      -     greater difficulties in accounts receivable collection;

      -     longer payment cycles;

      -     exposure to currency fluctuations;

      -     political and economic instability; and

      -     the burdens of complying with a wide variety of foreign laws and
            regulatory requirements.

      SPSS also believes that it is exposed to greater levels of software piracy
in certain international markets where weaker protection is afforded to
intellectual property. As SPSS expands its international operations, the risks
described above could increase and, in any event, could have a material adverse
effect on SPSS.

                 THE SPSS STOCK PRICE MAY EXPERIENCE VOLATILITY

      There has been significant volatility in the market prices of securities
of technology companies, including SPSS, and, in some instances, this volatility
has been unrelated to the operating performance of those companies. Market
fluctuations may adversely affect the price of the Company's common stock. SPSS
also believes that, in addition to factors such as interest rates and economic
conditions which affect stock prices generally, some, but not all, of the
factors which could result in fluctuations in its stock price include:

      -     announcements of new products by SPSS or its competitors;

      -     quarterly variations in financial results;

      -     recommendations and reports of analysts;

      -     acquisitions; and

      -     other factors beyond the control of SPSS.

                                       4
SPSS RELIES ON THIRD PARTIES FOR CERTAIN SOFTWARE

      SPSS licenses software from third parties. Some of this licensed software
is embedded in the Company's products, and some is offered as add-on products.
If these licenses are discontinued, or become invalid or unenforceable, there
can be no assurance that SPSS will be able to develop substitutes for this
software independently or to obtain alternative sources in a timely manner. Any
delays in obtaining or developing substitutes for licensed software could have a
material adverse effect on SPSS.

             SPSS RELIES ON THIRD PARTIES FOR SOFTWARE DISTRIBUTION

      In January 1997, SPSS entered into the Banta Global Turnkey Software
Distribution Agreement under which Banta Global Turnkey manufactures, packages
and distributes the Company's software products to the Company's domestic and
international customers and various international subsidiaries. The Banta
agreement had an initial three-year term and automatically renews thereafter for
successive periods of one year. The Banta agreement was renewed in January 2004.
Either party may terminate the Banta agreement for cause by written notice if
the other materially breaches its obligations. If Banta fails to perform
adequately any of its obligations under the Banta agreement, the Company's
operating results could be materially adversely affected.

                         CHANGES IN PUBLIC EXPENDITURES
                            MAY ADVERSELY AFFECT SPSS

      A significant portion of the revenues of SPSS comes from licenses of its
software directly to government entities both internationally and in the United
States. In addition, significant amounts of the Company's revenues come from
licenses to academic institutions, healthcare organizations and private
businesses that contract with or are funded by government entities. Government
appropriations processes are often slow and unpredictable and may be affected by
factors outside the Company's control. In addition, proposals are currently
being made in various countries to reduce government spending. Reductions in
government expenditures and termination or renegotiation of government-funded
programs or contracts could have a material adverse effect on SPSS. In addition,
declines in overall levels of economic activity could also have a material
adverse impact on SPSS.

                 SPSS MAY BE UNABLE TO CONTINUE TO COMPETE WITH
                 COMPANIES IN ITS INDUSTRIES THAT HAVE FINANCIAL
                               OR OTHER ADVANTAGES

      The Company's historical market for statistical software is both highly
competitive and fragmented. SPSS is among the largest companies in the
statistical software market, and, based upon sales and comparative assessments
in trade publications, SPSS believes that it competes effectively against its
competitors. SPSS considers its primary worldwide competitor to be the larger
and better-financed SAS Institute, although SPSS believes that the SAS
Institute's revenues are derived primarily from offerings in areas other than
predictive analytics. StatSoft Inc., Minitab Inc., Stata and Insightful are also
competitors, although their annual revenues from statistical products are
believed to be considerably less than the revenues of SPSS. In addition to
competition from other statistical software companies, SPSS also faces
competition from providers of software for specific statistical applications.

      In the market for data mining tools, the Company also competes with
offerings from Oracle, NCR, Fair Isaac, Angoss and Quadstone. In the market for
predictive analytic applications, SPSS also faces competition from well-financed
companies such as Siebel Systems, PeopleSoft, Fair Isaac and E.piphany. With the
exception of the SAS Institute, none of the Company's competitors are believed
to currently offer the range of predictive analytical capability provided by
SPSS.

                                       5
SPSS holds a strong position in the market for analytic applications to
the market research industry. SPSS believes no competitors in this market are
larger and better financed. The annual revenues of competitors such as Pulse
Train Technology, The Firm, Sawtooth Software, and Computers for Marketing
Corporation are thought to be considerably less than the market research
revenues of SPSS.

      In all markets, SPSS competes primarily on the basis of the usability,
functionality, performance, reliability and connectivity of its software. The
significance of each of these factors varies depending upon the anticipated use
of the software and the analytical training and expertise of the customer. To a
lesser extent, SPSS competes on the basis of price and thus maintains pricing
and licensing policies to meet market demand. SPSS believes it is able to
compete successfully because of the highly usable interfaces, comprehensive
analytical capabilities, efficient performance characteristics, local language
versions, consistent quality, connectivity capabilities, worldwide distribution
capabilities and widely recognized brand names.

      In the future, SPSS may face competition from new entrants into its
markets. SPSS could also experience competition from companies in other sectors
of the broader market for business intelligence software, like providers of OLAP
(On-Line Analytical Processing) and analytical application software, as well as
from companies in other sectors of the broader market for enterprise
applications, which could add enhanced analytical functionality to their
existing products. Some of these potential competitors have significant capital
resources, marketing experience and research and development capabilities.
Competitive pressures from the introduction of new solutions and products by
these companies or other companies could have a material adverse effect on SPSS.
There can be no assurance that SPSS will be able to compete successfully in the
future.

                 SPSS DEPENDS ON KEY EXECUTIVES; A LOSS OF THESE
                 EXECUTIVES AND OTHER PERSONNEL COULD NEGATIVELY
                              IMPACT OUR OPERATIONS

      SPSS is dependent on the efforts of various executives and key employees,
including its President and Chief Executive Officer, Jack Noonan. The continued
success of SPSS will depend in part on its ability to attract and retain highly
qualified technical, managerial, sales, marketing and other personnel.
Competition for highly qualified personnel is intense. The inability of SPSS to
continue to attract or retain highly qualified personnel could have a material
adverse effect on its financial position and results of operation. No life
insurance policies are maintained on SPSS key personnel.

                    SPSS MAY NOT RECEIVE THE FULL BENEFITS OF
                      ITS INTELLECTUAL PROPERTY PROTECTIONS

      The analytical algorithms incorporated in SPSS software are not
proprietary. SPSS believes that the proprietary technology constituting a
portion of its software determines the speed and quality of displaying the
results of computations, the ability of its software to work in conjunction with
third party software, and the ease of use of its software. The success of SPSS
will depend, in part, on its ability to protect the proprietary aspects of its
software. Attempts by SPSS to protect its proprietary software with trade secret
laws and internal nondisclosure safeguards, as well as copyright, trademark and
patent laws and contractual restrictions on copying, disclosure and
transferability that are incorporated into its software license agreements. SPSS
licenses its software only in the form of executable code, with contractual
restrictions on copying, disclosures and transferability. Except for licenses of
its products to users of large system products and annual licenses of its
desktop products, SPSS licenses its products to end-users by use of a
"shrink-wrap" license, as is customary in the industry. The source code for all
of

                                       6
SPSS software is protected as a trade secret and as unpublished copyrighted work
or patents. In addition, SPSS has entered into confidentiality and nondisclosure
agreements with its key employees. Despite these restrictions, the possibility
exists for competitors or users to copy aspects of SPSS products or to obtain
information which SPSS regards as a trade secret. Preventing unauthorized use of
computer software is difficult, and software piracy is expected to be a
persistent problem for the packaged software industry. These problems may be
particularly acute in international markets. In addition, the laws of various
countries in which SPSS software is or may be licensed do not protect its
software and intellectual property rights to the same extent as the laws of the
United States. Despite the precautions taken by SPSS, it may be possible for
unauthorized third parties to reverse engineer or copy SPSS products or obtain
and use information that SPSS regards as proprietary. There can be no assurance
that the steps taken by SPSS to protect its proprietary rights will be adequate
to prevent misappropriation of its technology.

      Although SPSS software has never been the subject of an infringement
claim, there can be no assurance that third parties will not assert infringement
claims against SPSS in the future or that any infringement assertion will not
result in costly litigation or require SPSS to obtain a license to use the
intellectual property of third parties. There can be no assurance that these
licenses will be available on reasonable terms, or at all. There can also be no
assurance that competitors of SPSS will not independently develop technologies
that are substantially equivalent or superior to SPSS technologies.

               CERTAIN STOCKHOLDERS AND OFFICERS AND DIRECTORS MAY
                     CONTROL CORPORATE ACTIONS DUE TO THEIR
                             OWNERSHIP OF SPSS STOCK

      The executive officers and directors of SPSS beneficially own a
significant percentage of its outstanding shares of common stock, currently
estimated to be approximately 15.25%. As a result, the officers and directors
may be able to influence important corporate decisions that require stockholder
approval. The Norman H. Nie Revocable Trust Dated March 15, 1991 (a trust
beneficially controlled by Norman H. Nie, the chairman of our board of
directors) and affiliates of the Norman H. Nie Trust currently own approximately
4.51% of the outstanding shares of SPSS common stock. If the Norman H. Nie Trust
and affiliates of the Norman H. Nie Trust own in the aggregate at least 12.50%
of the outstanding shares of SPSS common stock, the Norman H. Nie Trust would be
entitled to nominate a director for inclusion in the management slate for
election to the Board of Directors of SPSS.

      Because of the combined voting power of the officers and directors of
SPSS, these individuals acting as a group may be able to influence its affairs
and business, including any determination with respect to a change in control of
SPSS, future issuances of SPSS common stock or other securities, declaration of
dividends on SPSS common stock and the election of directors. This influence
could have the effect of delaying, deferring or preventing a change of control
of SPSS which could deprive SPSS stockholders of the opportunity to sell their
shares of common stock at prices higher than prevailing market prices.

                      ANTI-TAKEOVER PROTECTIONS MAY MAKE IT
                   DIFFICULT FOR A THIRD PARTY TO ACQUIRE SPSS

      SPSS maintains a stockholder Rights Agreement which was adopted by the
Board in 1998 and amended in June 2004. The Rights Agreement and common stock
purchase rights issued in connection with the Right Agreement are intended to
ensure that the Company's stockholders receive fair and equal treatment in the
event of a proposed takeover of SPSS. The Rights Agreement may discourage a
potential acquirer from acquiring control of SPSS.

                                       7
The SPSS Certificate of Incorporation and By-Laws contain a number of
provisions, including provisions requiring an 80% super-majority stockholder
approval of specified actions and provisions for a classified Board of
Directors, which would make the acquisition of SPSS, by means of an unsolicited
tender offer, a proxy contest or otherwise, more difficult. The bylaws of SPSS
provide for a staggered board of directors so that only one-third of the total
number of directors are replaced or re-elected each year. Therefore, potential
acquirers of SPSS may face delays in replacing the existing directors.

      Senior executives and other officers of SPSS may be entitled to
substantial payments in the event of their termination without cause or
constructive termination following a change of control of SPSS. These payments
could have the effect of discouraging a potential acquirer from acquiring
control of SPSS.

                    SALES OF SPSS STOCK AVAILABLE FOR FUTURE
                    USE COULD DEPRESS THE STOCK PRICE OF SPSS

      In addition to the shares of common stock which are outstanding, as of May
31, 2005, there were vested options outstanding held by management to purchase
approximately 1,417,158 additional shares of common stock, with an average
exercise price of $19.62 per share, and unvested options to purchase
approximately 506,060 additional shares of common stock. SPSS has also
established a stock purchase plan available to employees of SPSS, which permits
participating SPSS employees to purchase shares of common stock at the end of
each specified six-month period at the lesser of 85% of the market price of the
common stock on the first day of the six-month period and 85% of the market
price of the common stock on the last day of the six-month period.

      No prediction can be made as to the effect, if any, that future sales, or
the availability of shares of SPSS common stock for future sales, will have on
the market price prevailing from time to time. Sales of substantial amounts of
common stock by SPSS or by stockholders who hold "restricted securities," or the
perception that these sales may occur, could adversely affect prevailing market
prices for the common stock.

                     THE COMPANY MAY NOT MAINTAIN EFFECTIVE
                    INTERNAL CONTROL OVER FINANCIAL REPORTING

      As described in the Company's Annual Report on Form 10-K for fiscal year
2004 filed with the Securities and Exchange Commission on March 16, 2005, as
amended by a Form 10-K/A filed with the Securities and Exchange Commission on
April 22, 2005 (collectively, the "2004 Annual Report"), both Management's
report on Internal Control over Financial Reporting and the Attestation Report
of the Registered Public Accounting Firm indicated that the Company did not
maintain effective internal control over financial reporting as of December 31,
2004 because of material weaknesses related to revenue and income taxes. While
the Company has taken steps to remedy these material weaknesses, if the
resulting actions are not effective, or if SPSS has additional material
weaknesses during subsequent fiscal years, our financial statements could be
inaccurate. If we have inaccurate financial statements, it could have a material
adverse effect on the value of SPSS common stock.

                                       8
USE OF PROCEEDS

      All of the shares of SPSS common stock being offered by means of this
reoffer prospectus will be sold by the selling stockholders, who will receive
all proceeds from any sales. SPSS will, however, receive proceeds from the
initial sale of these shares to participants in the Stock Purchase Plan. All
proceeds received as a result of the purchase of common stock by participants in
the Stock Purchase Plan will be used as working capital for the Company's
operations. In addition, other than the completion and filing of this
registration statement, SPSS will not participate in the reoffering or sale of
the shares of common stock by the selling stockholders.

                              SELLING STOCKHOLDERS

      When an affiliate stockholder notifies SPSS that he or she intends to sell
any shares of common stock purchased by him or her under the Stock Purchase
Plan, the Company intends to file a supplement to this reoffer prospectus to
identify the name of each selling stockholder and the number of shares of SPSS
common stock to be reoffered by that selling stockholder. Specifically, SPSS
will update the following table to identify information with respect to the
beneficial ownership of its common stock by each selling stockholder immediately
before the offering and as adjusted to reflect the sale of shares of SPSS common
stock under the reoffering. The selling stockholders identified in any
supplement to this reoffer prospectus may from time to time offer the shares of
common stock offered by means of this reoffer prospectus. The Company does not
know when or in what amounts the selling stockholders may offer shares for
resale and it cannot assure investors that the selling stockholders will sell
any or all of the shares offered by means of this reoffer prospectus.
Shares Beneficially               Number of Shares            Shares Beneficially
                                            Owned Before the                 Available for               Owned After the
Selling Stockholders                          Offering(1)                   Reoffer and Sale                Offering(2)
--------------------                      --------------------              ----------------            -------------------
                                           Number   Percentage                  Hereby                   Number  Percentage
                                           ------   ----------                  ------                   ------  ----------
(1)   SPSS will rely on information provided by the selling stockholders
            to determine the number of shares of its common stock which the
            selling stockholders will own as of a particular date before the
            offering.

      (2)   Assumes the sale of all shares that may be sold in the offering, and
            that no other shares beneficially owned by the selling stockholders
            are sold.

                                       9
PLAN OF DISTRIBUTION

      The selling stockholders may, from time to time, sell all or a portion of
the shares covered by this reoffer prospectus by one or more of the following
methods:

      -     on the Nasdaq National Market, or such other exchange on which the
            SPSS common stock may from time to time be trading;

      -     in privately negotiated transactions or otherwise;

      -     at fixed prices that may be changed;

      -     at market prices prevailing at the time of the sale;

      -     at prices related to such market prices or at prices otherwise
            negotiated;

      -     in block trades in which the broker or dealer will attempt to sell
            the shares as agent but may position and resell a portion of the
            block as principal to facilitate the transaction;

      -     through purchases by a broker or dealer as principal;

      -     by an exchange distribution in accordance with the rules of such
            exchange;

      -     in ordinary brokerage transactions and transactions in which the
            broker solicits purchasers;

      -     through short sales; or

      -     by a combination of any of the above methods of sale.

      In effecting sales, brokers and dealers engaged by the selling
stockholders may arrange for other brokers or dealers to participate. Brokers or
dealers may receive commissions or discounts from the selling stockholders, or,
if any broker-dealer acts as agent for the purchaser of the shares, from the
purchaser, in amounts to be negotiated which are not expected to exceed those
customary in the types of transactions involved. Broker-dealers may agree with
the selling stockholders to sell a specified number of shares at a stipulated
price per share. To the extent a broker-dealer is unable to sell a specified
number of shares acting as agent for the selling stockholders, it will purchase
as principal any unsold shares at the price required to fulfill the
broker-dealer commitment to the selling stockholders. Broker-dealers who acquire
shares as principal may resell the shares from time to time in transactions that
may involve block transactions of the nature described above, in the
over-the-counter market, at prices and on terms then prevailing at the time of
sale, at prices related to the then-current market price or in negotiated
transactions. In connection with resales, broker-dealers may pay to or receive
from the purchasers of the shares commissions as described above.

      The selling stockholders may be deemed "underwriters" as defined in the
Securities Act of 1933 in connection with the sale of the shares offered by this
reoffer prospectus. Any broker-dealers or agents that participate with the
selling stockholders in sales of the shares may be considered to be
"underwriters" within the meaning of the Securities Act of 1933 in connection
with sales in which they

                                       10
participate. If any broker-dealers or agents are considered to be
"underwriters," then any commissions they receive and any profit on the resale
of the shares purchased by them may be considered to be underwriting commissions
or discounts under the Securities Act of 1933.

      The selling stockholders and any other persons participating in the sale
or distribution of the shares will be subject to the Securities Exchange Act of
1934 and related rules and regulations, including Regulation M, to the extent it
applies. The Securities Exchange Act of 1934 and related rules may limit the
timing of purchases and sales of any of the shares by the selling stockholders,
or any other person, that may affect the marketability of the shares. The
selling stockholders also must comply with the applicable prospectus delivery
requirements under the Securities Act of 1933 in connection with the sale or
distribution of the shares.

      SPSS is required to pay certain fees and expenses incident to the
registration of the shares for resale by the selling stockholders.

      SPSS has agreed to indemnify the selling stockholders in certain
circumstances against certain liabilities, including liabilities under the
Securities Act of 1933. The selling stockholders have agreed to indemnify SPSS
in certain circumstances against certain liabilities, including liabilities
under the Securities Act of 1933.

      This offering will terminate on the date on which the selling stockholders
have sold all shares offered by means of this reoffer prospectus.

                                  LEGAL MATTERS

      The legality of the shares of our common stock being offered by means of
this reoffer prospectus has been passed on for SPSS by McGuireWoods LLP,
Chicago, Illinois.

                                     EXPERTS

      The consolidated financial statements and schedule of SPSS Inc. (the
Company) as of December 31, 2004 and 2003, and for each of the years in the
three-year period ended December 31, 2004, and management's assessment of the
effectiveness of internal control over financial reporting as of December 31,
2004 have been incorporated by reference herein and in the registration
statement in reliance upon the reports of KPMG LLP, independent registered
public accounting firm, incorporated by reference herein, and upon the authority
of said firm as experts in accounting and auditing.

      The audit report on management's assessment of the effectiveness of
internal control over financial reporting and the effectiveness of internal
control over financial reporting as of December 31, 2004, expresses the opinion
that the Company did not maintain effective internal control over financial
reporting as of December 31, 2004 because of the effect of the material
weaknesses on the achievement of the objectives of the control criteria and
contains explanatory paragraphs that state SPSS Inc. did not maintain effective
internal control over financial reporting as of December 31, 2004, because of
the effect of the material weaknesses identified in management's assessment
associated with the Company's accounting for revenue and income taxes.

                                       11
WHERE INVESTORS CAN FIND MORE INFORMATION

      SPSS has filed a registration statement on Form S-8 with the SEC under the
Securities Act of 1933, to allow the selling stockholders to resell the common
stock offered by means of this reoffer prospectus. This reoffer prospectus,
which is a part of the registration statement, does not contain all of the
information identified in the registration statement. For further information
about the Company and the common stock offered by means of this reoffer
prospectus, please refer to the registration statement and the exhibits filed as
a part of the registration statement. Statements contained in this reoffer
prospectus as to the contents of any contract or other document filed as an
exhibit to the registration statement are not necessarily complete. If a
contract or document has been filed as an exhibit to the registration statement,
the Company refers investors to the copy of the contract or document that has
been filed.

      SPSS is subject to the information and periodic reporting requirements of
the Securities Exchange Act of 1934. In accordance with those requirements, SPSS
files annual, quarterly and special reports, proxy statements and other
information with the SEC. Investors can read and copy any document the Company
files at the SEC's public reference rooms at the following location:

                           Judiciary Plaza
                           450 Fifth Street, N.W.
                           Room 1024
                           Washington, D.C., 20549

      Investors can request copies of these documents upon payment of a
duplicating fee, by writing to the SEC. Please call the SEC at 1-800-SEC-0330
for further information on the operation of the public reference rooms and the
procedure for obtaining copies.

      The SEC maintains an Internet site that contains reports, proxy and
information statements, and other information regarding issuers that file
electronically with the SEC. The documents that SPSS files with the SEC,
including the registration statement, are available to investors on this web
site. Investors can log onto the SEC's web site at http://www.sec.gov. Certain
information is also available at the SPSS website at http://www.spss.com.

                      INFORMATION INCORPORATED BY REFERENCE

      The SEC allows SPSS to "incorporate by reference" the information that the
Company files with the SEC, which means that SPSS can disclose important
information to investors by referring to those documents. As a result, investors
may need to review other documents filed by SPSS with the SEC to obtain more
information. Information is incorporated into this reoffer prospectus in two
ways. First, if information is contained in a document that SPSS filed with the
SEC before the date of this reoffer prospectus, the document is specifically
identified below. Second, all of the information provided in a periodic or other
report or proxy statement filed by SPSS with the SEC after the date of this
reoffer prospectus and before the date that the offering described in this
reoffer prospectus is terminated is incorporated by reference.

      The information contained in the documents the Company incorporates by
reference is considered a part of this reoffer prospectus. Additionally, because
information concerning SPSS,

                                       12
whether contained in this reoffer prospectus or in a document incorporated by
reference, will be amended or superseded by more current information contained
in later filed documents, the information that SPSS files with the SEC after the
date of this reoffer prospectus will update and supersede older information
contained in, or incorporated by reference into, this reoffer prospectus.

      SPSS incorporates by reference into this reoffer prospectus all the
documents listed below:

      -     The annual report of SPSS Inc. on Form 10-K filed with the SEC on
            March 16, 2005 for the fiscal year ended December 31, 2004, as
            amended by that certain Amendment No. 1 to Annual Report on Form
            10-K/A filed with the SEC on April 22, 2005.

      -     The quarterly report of SPSS Inc. on Form 10-Q filed with the SEC on
            May 6, 2005 for the fiscal quarter ended March 31, 2005.

      -     The current report of SPSS Inc. on form 8-K, dated June 15, 2005,
            filed with the SEC on June 15, 2005. The Form 8-K reported that
            the SPSS stockholders approved, and the Company adopted, the SPSS
            Inc. Employee Stock Purchase Plan.

      -     The current report of SPSS Inc. on Form 8-K, dated May 6, 2005,
            filed with the SEC on May 12, 2005. The Form 8-K reported that the
            SPSS Audit Committee dismissed KPMG LLP as the Company's independent
            auditors and engaged Grant Thornton LLP as the Company's independent
            auditors. The Form 8-K attached a letter from KPMG LLP to the SEC.

      -     The current report of SPSS Inc. on Form 8-K, dated May 4, 2004,
            filed with the SEC on May 6, 2005. The Form 8-K reported that SPSS
            had held its First Quarter 2005 Earnings Release Conference Call on
            May 4, 2004. The Form 8-K attached a transcript of the conference
            call as an exhibit.

      -     The current report of SPSS Inc. on Form 8-K, dated May 3, 2005,
            filed with the SEC on May 4, 2005. The Form 8-K reported that SPSS
            had issued a press release announcing its results for the fiscal
            quarter ended March 31, 2005 and attached a copy of the press
            release as an exhibit.

      -     The current report of SPSS Inc. on Form 8-K, dated April 28, 2005,
            filed with the SEC on May 2, 2005. The Form 8-K reported that the
            Company amended and restated the change of control agreements that
            it maintains with certain executive officers, and the Company
            entered into new change of control agreements with additional
            officers.

      -     The current report of SPSS Inc. on Form 8-K, dated April 28, 2005,
            filed with the SEC on April 28, 2005. The Form 8-K reported that the
            Company's Board of Directors ratified an amendment to the SPSS Inc.
            Code of Business Conduct and Ethics to modify the procedure by which
            questions or concerns regarding the Company's accounting methods,
            internal accounting controls, auditing matters or procedures for
            reporting financial information may be reported to the Audit
            Committee of the Board of Directors.

                                       13
-     The current report of SPSS Inc. on Form 8-K, dated April 28, 2005,
            filed with the SEC on April 28, 2005. The Form 8-K reported that the
            Company's Board of Directors had set annual base salaries and bonus
            targets for the Company's senior executive officers.

      -     The current report of SPSS Inc. in Form 8-K, dated March 14, 2005,
            filed with the SEC on March 14, 2005. The Form 8-K reported that the
            Company amended and restated its employment agreement with Mr.
            Raymond Panza, the Company's Executive Vice President, Corporate
            Operations, Chief Financial Officer and Secretary.

      -     The current report of SPSS Inc. in Form 8-K, dated March 14, 2005,
            filed with the SEC on March 14, 2005. The Form 8-K reported that the
            Company amended and restated its employment agreement with Mr. Jack
            Noonan, the Company's President and Chief Executive Officer.

      -     The current report of SPSS Inc. in Form 8-K, dated February 16,
            2005, filed with the SEC on February 18, 2005. The Form 8-K reported
            that SPSS had held its Fourth Quarter and Fiscal Year 2004 Earnings
            Release Conference Call on February 16, 2005. The Form 8-K attached
            a transcript of the conference call as an exhibit.

      -     The current report of SPSS Inc. in Form 8-K, dated February 15,
            2005, filed with the SEC on February 16, 2005. The Form 8-K reported
            that SPSS had issued a press release announcing its results for the
            fiscal quarter ended December 31, 2004 and for fiscal year 2004 and
            attached a copy of the press release as an exhibit.

      -     The proxy statement, filed with the SEC on May 16, 2005, for the
            SPSS annual meeting of stockholders held on June 15, 2005, except
            for the compensation committee report contained therein.

      -     The description of the common stock of SPSS Inc. contained in its
            registration statement filed with the SEC on a Form 8-A dated August
            4, 1993, as amended by the Form 8-A12G/A dated August 31, 2004,
            pursuant to Section 12 of the Securities Exchange Act of 1934.

      In addition to the documents listed above, SPSS incorporates by reference
into this reoffer prospectus all documents filed by SPSS with the SEC under
Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as
amended, after the date of this reoffer prospectus and until all shares of the
common stock being offered by means of this reoffer prospectus have been sold by
the selling stockholders or the registration statement which SPSS has filed with
the SEC relating to the common stock ceases to be effective.

      SPSS will deliver a free copy of any document incorporated by reference
into this reoffer prospectus but not delivered with this reoffer prospectus to
anyone who receives this reoffer prospectus. Exhibits filed with the documents
that are incorporated by reference into this reoffer prospectus will be
delivered only if the exhibits have been specifically incorporated by reference.
Requests for any of these documents may be made in writing or orally and should
be directed to: Chief Financial Officer, SPSS Inc., 233 South Wacker Drive, 11th
Floor, Chicago, Illinois 60606, (312) 651-3000.

                                       14
No dealer, salesperson, or any other person has been authorized to give
any information or to make any representation not contained in this reoffer
prospectus. Any information or representation not contained herein must not be
relied upon as having been authorized by SPSS or any selling stockholder. This
reoffer prospectus does not constitute an offer to sell, or a solicitation of an
offer to buy, any securities other than the securities covered by this reoffer
prospectus; nor does it constitute an offer to sell, or a solicitation of an
offer to buy, any of the securities covered by this reoffer prospectus by SPSS
or any selling stockholder in any state where such offer or solicitation is not
permitted. Neither the delivery of this reoffer prospectus nor any sale made
hereunder shall, under any circumstances, create an implication that there has
been no change in the affairs of SPSS since the date on the front of this
document.

      All selling stockholders that effect transactions in the shares of common
stock offered by means of this prospectus are required to deliver a copy of
their prospectus to any purchaser of the shares of common stock at or before the
time a certificate representing the shares of common stock is delivered to the
purchaser.

                                       15
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item  3. Incorporation of Certain Documents by Reference

      The SEC allows SPSS to "incorporate by reference" the information that the
Company files with the SEC, which means that SPSS can disclose important
information to investors by referring to those documents. As a result, investors
may need to review other documents filed by SPSS with the SEC to obtain more
information. The information contained in the documents SPSS incorporates by
reference is considered a part of this registration statement. Additionally,
because information concerning SPSS, whether contained in this registration
statement or in a document incorporated by reference, will be amended or
superseded by more current information contained in later filed documents, the
information that SPSS files with the SEC after the date of this registration
statement, and before the filing of a post-effective amendment to this
registration statement which indicates that all securities offered by this
registration statement have been sold or which deregisters all securities
remaining unsold, will update and supersede older information contained in, or
incorporated by reference into, this registration statement.

      SPSS hereby incorporates by reference the following documents previously
filed with the SEC:

            (a)   The annual report of SPSS Inc. on Form 10-K filed with the SEC
                  on March 16, 2005 for the fiscal year ended December 31, 2004,
                  as amended by that certain Amendment No. 1 to Annual Report on
                  Form 10-K/A filed with the SEC on April 22, 2005.

            (b)   The quarterly report of SPSS Inc. on Form 10-Q filed with the
                  SEC on May 6, 2005 for the fiscal quarter ended March 31,
                  2005.

            (c)   The current report of SPSS Inc. on form 8-K, dated June 15,
                  2005, filed with the SEC on June 15, 2005. The Form 8-K
                  reported that the SPSS stockholders approved, and the Company
                  adopted, the SPSS Inc. Employee Stock Purchase Plan.

            (d)   The current report of SPSS Inc. on Form 8-K, dated May 6,
                  2005, filed with the SEC on May 12, 2005. The Form 8-K
                  reported that the SPSS Audit Committee dismissed KPMG LLP as
                  the Company's independent auditors and engaged Grant Thornton
                  LLP as the Company's independent auditors. The Form 8-K
                  attached a letter from KPMG LLP to the SEC.

            (e)   The current report of SPSS Inc. on Form 8-K, dated May 4,
                  2004, filed with the SEC on May 6, 2005. The Form 8-K reported
                  that SPSS had held its First Quarter 2005 Earnings Release
                  Conference Call on May 4, 2004. The Form 8-K attached a
                  transcript of the conference call as an exhibit.

            (f)   The current report of SPSS Inc. on Form 8-K, dated May 3,
                  2005, filed with the SEC on May 4, 2005. The Form 8-K reported
                  that SPSS had issued a press release

                                      II-1
announcing its results for the fiscal quarter ended March 31,
                  2005 and attached a copy of the press release as an exhibit.

            (g)   The current report of SPSS Inc. on Form 8-K, dated April 28,
                  2005, filed with the SEC on May 2, 2005. The Form 8-K reported
                  that the Company amended and restated the change of control
                  agreements that it maintains with certain executive officers,
                  and the Company entered into new change of control agreements
                  with additional officers.

            (h)   The current report of SPSS Inc. on Form 8-K, dated April 28,
                  2005, filed with the SEC on April 28, 2005. The Form 8-K
                  reported that the Company's Board of Directors ratified an
                  amendment to the SPSS Inc. Code of Business Conduct and Ethics
                  to modify the procedure by which questions or concerns
                  regarding the Company's accounting methods, internal
                  accounting controls, auditing matters or procedures for
                  reporting financial information may be reported to the Audit
                  Committee of the Board of Directors.

            (i)   The current report of SPSS Inc. on Form 8-K, dated April 28,
                  2005, filed with the SEC on April 28, 2005. The Form 8-K
                  reported that the Company's Board of Directors had set annual
                  base salaries and bonus targets for the Company's senior
                  executive officers.

            (j)   The current report of SPSS Inc. in Form 8-K, dated March 14,
                  2005, filed with the SEC on March 14, 2005. The Form 8-K
                  reported that the Company amended and restated its employment
                  agreement with Mr. Raymond Panza, the Company's Executive Vice
                  President, Corporate Operations, Chief Financial Officer and
                  Secretary.

            (k)   The current report of SPSS Inc. in Form 8-K, dated March 14,
                  2005, filed with the SEC on March 14, 2005. The Form 8-K
                  reported that the Company amended and restated its employment
                  agreement with Mr. Jack Noonan, the Company's President and
                  Chief Executive Officer.

            (l)   The current report of SPSS Inc. in Form 8-K, dated February
                  16, 2005, filed with the SEC on February 18, 2005. The Form
                  8-K reported that SPSS had held its Fourth Quarter and Fiscal
                  Year 2004 Earnings Release Conference Call on February 16,
                  2005. The Form 8-K attached a transcript of the conference
                  call as an exhibit.

            (m)   The current report of SPSS Inc. in Form 8-K, dated February
                  15, 2005, filed with the SEC on February 16, 2005. The Form
                  8-K reported that SPSS had issued a press release announcing
                  its results for the fiscal quarter ended December 31, 2004 and
                  for fiscal year 2004 and attached a copy of the press release
                  as an exhibit.

            (n)   The proxy statement, filed with the SEC on May 16, 2005, for
                  the SPSS annual meeting of stockholders held on June 15, 2005,
                  except for the compensation committee report contained
                  therein.

                                      II-2
(o)   The description of the common stock of SPSS Inc. contained in
                  its registration statement filed with the SEC on a Form 8-A
                  dated August 4, 1993, as amended by the Form 8-A12G/A dated
                  August 31, 2004, pursuant to Section 12 of the Securities
                  Exchange Act of 1934.

      In addition to the documents listed above, SPSS incorporates by reference
into this registration statement all documents filed by SPSS with the SEC under
Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934 after
the date of this registration statement and prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all securities then remaining unsold.

Item  4. Description of Securities

            Not applicable.

Item  5. Interests of Named Experts and Counsel

            Not applicable.

Item  6. Indemnification of Officers and Directors

      The SPSS Certificate of Incorporation provides for indemnification to the
full extent permitted by the laws of the State of Delaware against, and with
respect to, threatened, pending or completed actions, suits or proceedings
arising from, or alleged to arise from, a party's actions or omissions as a
director, officer, employee or agent of SPSS or of any other corporation,
partnership, joint venture, trust or other enterprise which has served in such
capacity at the request of SPSS if the acts or omissions occurred, or were or
alleged to have occurred, while such party was a director or officer of SPSS.
Generally, under Delaware law, indemnification will only be available where an
officer or director can establish that he or she acted in good faith and in a
manner which was reasonably believed to be in, or not opposed to, the best
interests of SPSS.

      Section 145 of the Delaware General Corporation Law provides that a
corporation may indemnify any person made a party to an action, suit or
proceeding (other than an action by, or in the right of, the corporation) by
reason of the fact that the person is or was a director, officer, employee or
agent of the corporation, or is or was serving at the request of the
corporation, against expenses (including attorneys' fees), judgments, fines and
amounts paid in settlement actually and reasonably incurred by such person in
connection with such action, suit or proceeding, if such person acted in good
faith and in a manner such person reasonably believed to be in, or not opposed
to, the best interests of the corporation, and, with respect to any criminal
action or proceeding, had no reasonable cause to believe such person's conduct
was unlawful.

      In addition, Section 145 provides that a corporation may indemnify any
person made a party to an action, suit or proceeding by or in the right of the
corporation to procure a judgment in its favor by reason of the fact that the
person is or was a director, officer, employee or agent of

                                      II-3
the corporation, or is or was serving at the request of the corporation, against
expenses (including attorneys' fees) actually and reasonably incurred by such
person in connection with the defense or settlement of such action or suit if
such person acted in good faith and in a manner such person reasonably believed
to be in, or not opposed to, the best interests of the corporation and except
that no indemnification shall be made in respect of any claim, issue or matter
as to which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Delaware Court of Chancery or the court
in which such action or suit was brought shall determine upon application that,
despite the adjudication of liability but in view of all the circumstances of
the case, such person is fairly and reasonably entitled to indemnity for such
expenses which the court shall deem proper.

      Section 145 also provides that to the extent a director, officer, employee
or agent of a corporation has been successful on the merits or otherwise in
defense of any action, suit or proceeding referred to above, or defense of any
claim, issue or matter therein, he or she shall be indemnified against expenses
(including attorneys' fees) actually and reasonable incurred in connection
therewith.

      Under the applicable provisions of the Delaware General Corporation Law,
any indemnification described above shall be made by the corporation only as
authorized in the specific case upon a determination that the indemnification of
the director, officer, employee or agent is proper under the circumstances
because he or she has met the applicable standard of conduct. Such determination
shall be made:

      (1)   by the Board of Directors by a majority vote of directors who are
            not parties to such action, suit or proceeding, even though less
            than a quorum; or

      (2)   by a committee of directors who are not parties to the action, suit
            or proceeding, as designated by a majority vote of such directors,
            even though less than a quorum; or

      (3)   if no directors who are not parties to the action, suit, or
            proceeding exist, or if such directors so direct, by independent
            legal counsel in a written opinion; or

      (4)   by the affirmative vote of a majority of the shares entitled to vote
            thereon.

Item  7. Exemption from Registration Claimed.

            Not applicable.

Item  8. Exhibits.
Exhibit                                                                                                        Incorporation
 Number       Description                                                                                       by Reference
-------       -----------                                                                                      -------------
5.1        Opinion of McGuireWoods LLP regarding legality of shares of Common Stock.
II-4
10.55        SPSS Inc. Employee Stock Purchase Plan.                                                                   (1)
 23.1        Consent of KPMG LLP.
 23.2        Consent of McGuireWoods LLP (contained in opinion filed as Exhibit 5.1).
 24.1        Power of Attorney (contained within the signature page to the Registration Statement on Form S-8).        (2)
(1)   Previously filed with the Report on Form 8-K of SPSS Inc., dated June 15,
      2005 filed on June 15, 2005. (File No. 000-22194)

(2)   Power of attorney is contained within the signature page.

Item  9. Undertakings.

      (a) The undersigned registrant hereby undertakes:

            (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement:

                  To include any material information with respect to the plan
      of distribution not previously disclosed in this registration statement or
      any material change to such information in the registration statement.

            (2) That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

            (3) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

      (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Securities Exchange Act of
1934) that is incorporated by reference in the registration statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.

      (c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the registrant pursuant to the foregoing provisions, or otherwise,
the registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Securities Act of 1933 and is, therefore, unenforceable. In the event
that a claim for indemnification against such liabilities (other than the
payment by the registrant of expenses

                                      II-5
incurred or paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act of 1933 and will be governed by the
final adjudication of such issue.

                                      II-6
SIGNATURES

      Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Chicago, State of Illinois, on June 15, 2005.

                                      SPSS Inc.

                                      By: /s/ Jack Noonan
                                          -------------------------------------
                                          Jack Noonan
                                          President and Chief Executive Officer

                                POWER OF ATTORNEY

      Each person whose signature appears below hereby constitutes and appoints
Jack Noonan and Raymond H. Panza, and each of them, the true and lawful
attorneys-in-fact and agents of the undersigned, with full power of substitution
and resubstitution, for and in the name, place and stead of the undersigned, in
any and all capacities, to sign any and all amendments (including post-effective
amendments) to this registration statement, and to file the same, with all
exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, and hereby grants to such attorneys-in-fact
and agents, and each of them, full power and authority to do and perform each
and every act and thing requisite and necessary to be done in furtherance of the
foregoing, as fully to all intents and purposes as the undersigned might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or any of them, or their or his substitute or
substitutes, may lawfully do or cause to be done by virtue hereof.

      Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities indicated on June 15, 2005.
Signature                                  Title(s)
---------                                  --------
/s/ Norman H. Nie              Chairman of the Board of Directors
--------------------
Norman H. Nie

/s/ Jack Noonan                President, Chief Executive Officer and Director
--------------------
Jack Noonan

/s/ Raymond H. Panza           Executive Vice President, Corporate Operations,
--------------------           Chief Financial Officer and Secretary
Raymond H. Panza
II-7
/s/ Marc D. Nelson             Corporate Controller
---------------------------
Marc D. Nelson

/s/ Michael Blair              Director
---------------------------
Michael Blair

/s/ Charles R. Whitchurch      Director
---------------------------
Charles R. Whitchurch

/s/ Merritt Lutz               Director
---------------------------
Merritt Lutz

/s/ Promod Haque               Director
---------------------------
Promod Haque

/s/ William Binch              Director
---------------------------
William Binch

/s/ Kenneth Holec              Director
---------------------------
Kenneth Holec
II-8
SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                               EXHIBITS FILED WITH

                                    FORM S-8

                             REGISTRATION STATEMENT

                                      UNDER

                           THE SECURITIES ACT OF 1933

                                    SPSS INC.
SPSS INC.

                                  EXHIBIT INDEX
Exhibit
  No.         Description
-------       -----------
5.1        Opinion of McGuireWoods LLP regarding legality of shares of Common Stock.
 10.55        SPSS Inc. Employee Stock Purchase Plan.(1)
  23.1        Consent of KPMG LLP.
  23.2        Consent of McGuireWoods LLP (contained in opinion filed as Exhibit 5.1).
  24.1        Power of Attorney (contained within the signature page to the Registration Statement on Form S-8).
(1)   Previously filed with the Report on Form 8-K of SPSS Inc., dated June 15,
      2005 filed on June 15, 2005. (File No. 000-22194)

                                       2