As filed with the Securities and Exchange Commission on June 28, 2001
                                               REGISTRATION NO. 333-_______
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                               ------------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                              ---------------------

                       NETWORK-1 SECURITY SOLUTIONS, INC.
             (Exact name of registrant as specified in its charter)


           DELAWARE                                             11-3027591
(State or other jurisdiction                                 (I.R.S. employer
     of incorporation)                                    identification number)


                       1601 TRAPELO ROAD, RESERVOIR PLACE
                          WALTHAM, MASSACHUSETTS 02451
                                 (781) 522-3400
    (Address, including zip code, and telephone number, including area code,
                  of Registrant's principal executive offices)

                             ----------------------

                       NETWORK-1 SECURITY SOLUTIONS, INC.
                   AMENDED AND RESTATED 1996 STOCK OPTION PLAN
                            (Full title of the plan)

                             ----------------------

                                 MURRAY P. FISH
                      PRESIDENT AND CHIEF FINANCIAL OFFICER
                       NETWORK-1 SECURITY SOLUTIONS, INC.
                       1601 TRAPELO ROAD, RESERVOIR PLACE
                          WALTHAM, MASSACHUSETTS 02451
                                 (781) 522-3400
               (Address, including zip code, and telephone number,
                   including area code, of agent for service)

                             -----------------------

                                   COPIES TO:
                               SAM SCHWARTZ, ESQ.
                 OLSHAN GRUNDMAN FROME ROSENZWEIG & WOLOSKY LLP
                                 505 PARK AVENUE
                            NEW YORK, NEW YORK 10022
                                 (212) 753-7200

================================================================================
<PAGE>
<TABLE><CAPTION>

                         CALCULATION OF REGISTRATION FEE
===========================================  =================  ==============  ==================  ============
                                                                   PROPOSED
                                                                   MAXIMUM       PROPOSED MAXIMUM     AMOUNT OF
                                                AMOUNT TO BE    OFFERING PRICE  AGGREGATE OFFERING  REGISTRATION
TITLE OF SECURITIES TO BE REGISTERED         REGISTERED (1)(2)   PER SHARE (3)       PRICE (3)          FEE
-------------------------------------------  -----------------  --------------  ------------------  ------------
<S>                                          <C>                <C>             <C>                 <C>
Common Stock, par value $.01 per share.....    735,000 shares      $1.71          $1,258,432          $314.61
===========================================  =================  ==============  ==================  ============
</TABLE>

(1)  Represents the aggregate number of shares of common stock, par value $.01
     per share (the "Common Stock"), of Network-1 Security Solutions, Inc. (the
     "Company") issuable upon exercise of stock options granted or to be granted
     by the Company under its Amended and Restated 1996 Stock Option Plan, as
     amended and restated to date (the "Plan"), for which no registration
     statement has been filed. A registration statement (Registration No.
     333-93895) covering the other 1,800,000 shares of Common Stock issuable
     upon exercise of stock options granted under the Plan was filed on December
     30, 1999.

(2)  Pursuant to Rule 416, this registration statement also covers such
     indeterminate additional shares of Common Stock as may become issuable as a
     result of any future anti-dilution adjustment in accordance with the terms
     of the Plan.

(3)  Pursuant to Rule 457(h) promulgated under the Securities Act, includes (i)
     an aggregate of 244,268 shares with respect to which options have been
     granted under the Plan at an average exercise price of $ 3.0625 and (ii) an
     additional 490,732 shares which may be offered under the Plan at a price,
     based on the average of the high and low sales prices for the shares of
     Common Stock as reported on The Nasdaq Stock Market's SmallCap Market on
     June 26, 2001, of $1.04.

<PAGE>


                                EXPLANATORY NOTES


         On December 30, 1999, Network-1 Security Solutions, Inc. (the
"Company") filed a Registration Statement on Form S-8 (Registration No.
333-93895) registering 1,800,000 shares of the Company's common stock, par value
$.01 per share (the "Common Stock"), issuable upon exercise of stock options
granted by the Company under its Amended and Restated 1996 Stock Option Plan, as
amended and restated as of such date (the "Plan"). The Company has prepared this
Registration Statement in accordance with the requirements of Form S-8 under the
Securities Act of 1933, as amended (the "Securities Act"), to register the
735,000 additional shares of Common Stock issuable upon exercise of stock
options that have been added to the Plan.

         This Form S-8 includes a Reoffer Prospectus prepared in accordance with
Part I of Form S-3 under the Securities Act. The Reoffer Prospectus may be
utilized for reofferings and resales of shares of Common Stock acquired pursuant
to the Plan by selling stockholders who may be deemed "affiliates" (as such term
is defined in Rule 405 under the Securities Act) of the Company. Some of these
shares were previously registered.





                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS

         The Company will provide documents containing the information specified
in Part 1 of Form S-8 to employees as specified by Rule 428(b)(1) under the
Securities Act. Pursuant to the instructions to Form S-8, the Company is not
required to file these documents either as part of this Registration Statement
or as prospectuses or prospectus supplements pursuant to Rule 424 under the
Securities Act.
<PAGE>

                                   PROSPECTUS

                                 886,518 SHARES
                       NETWORK-1 SECURITY SOLUTIONS, INC.
                          COMMON STOCK ($.01 PAR VALUE)


         This prospectus relates to the reoffer and resale by certain selling
stockholders of shares of our common stock that may be issued by us to the
selling stockholders upon the exercise of stock options granted under our Stock
Option Plan. We previously registered the offer and sale of the shares to the
selling stockholders. This prospectus also relates to certain underlying options
that have not as of this date been granted. If and when such options are granted
to persons required to use this prospectus to reoffer and resell the shares
underlying such options, we will distribute a prospectus supplement. The shares
are being reoffered and resold for the account of the selling stockholders and
we will not receive any of the proceeds from the resale of the shares.

         The selling stockholders have advised us that the resale of their
shares may be effected from time to time in one or more transactions on The
Nasdaq Stock Market's SmallCap Market, in negotiated transactions or otherwise,
at market prices prevailing at the time of the sale or at prices otherwise
negotiated. See "Plan of Distribution." We will bear all expenses in connection
with the preparation of this prospectus.

         Our common stock is listed on The Nasdaq Stock Market's SmallCap
Market. On June 26, 2001, the closing price for our Common Stock, as reported by
the Nasdaq SmallCap Market, was $1.04.


THE SECURITIES OFFERED IN THIS PROSPECTUS INVOLVE A HIGH DEGREE OF RISK. YOU
SHOULD CAREFULLY CONSIDER THE FACTORS DESCRIBED UNDER THE HEADING "RISK FACTORS"
BEGINNING ON PAGE 4 OF THIS PROSPECTUS.



--------------------------------------------------------------------------------

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

--------------------------------------------------------------------------------





                  THE DATE OF THIS PROSPECTUS IS JUNE 28, 2001.
<PAGE>



                                TABLE OF CONTENTS


                                                                            PAGE
                                                                            ----


ABOUT THIS PROSPECTUS.......................................................  2


WHERE YOU CAN FIND MORE INFORMATION.........................................  2


INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.............................  2


NOTE REGARDING FORWARD-LOOKING STATEMENTS...................................  3


RISK FACTORS................................................................  4


THE COMPANY.................................................................  8


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


SELLING STOCKHOLDERS........................................................ 10


PLAN OF DISTRIBUTION........................................................ 13


LEGAL MATTERS............................................................... 14


EXPERTS..................................................................... 14


DISCLOSURE OF COMMISSION POSITION ON........................................ 14


INDEMNIFICATION FOR SECURITIES ACT LIABILITIES.............................. 14










                                        i
<PAGE>
                              ABOUT THIS PROSPECTUS

         This prospectus is part of a registration statement we filed with the
Securities and Exchange Commission (the "SEC") and therefore omits certain
information in such registration statement. We have also filed exhibits with the
registration statement that are not included in this prospectus, and you should
refer to the applicable exhibit for a complete description of any statement
referring to any document. You can inspect a copy of the registration statement
and its exhibits, without charge, at the SEC's public reference room, and can
copy such material upon paying the SEC's prescribed rates.

         You should rely only on the information and representations provided or
incorporated by reference in this prospectus or any related supplement. We have
not authorized anyone else to provide you with different information. The
Selling Stockholders will not make an offer of these shares in any state where
the offer is not permitted. You should not assume that the information in this
prospectus or any supplement is accurate as of any date other than the date on
the front of those documents.

                       WHERE YOU CAN FIND MORE INFORMATION

         We file annual, quarterly and special reports, proxy statements and
other information with the SEC. You may read and copy any document we file at
the SEC's public reference room located at Judiciary Plaza, 450 Fifth Street,
N.W., Washington, D.C. 20549. The SEC has prescribed rates for copying. You may
obtain further information on the operation of the public reference room by
calling the SEC at 1-800-SEC-0330. Our SEC filings are also available to the
public over the Internet at the SEC's web site at http://www.sec.gov.

                 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

         The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information we incorporate by reference is
considered to be a part of this prospectus and information that we file later
with the SEC will automatically update and replace the information in this
prospectus. Accordingly, we incorporate by reference the documents listed below
and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or
15(d) of the Securities Exchange Act of 1934, as amended:

     1.  Our Report on Form 8-K filed with the SEC on June 15, 2001;

     2.  Our Quarterly Report on Form 10-QSB for the quarterly period ended
         March 31, 2001;

     3.  Our Annual Report on Form 10-KSB for the year ended December 31, 2000;
         and

     4.  The description of our common stock incorporated by reference in our
         Registration Statement on Form 8-A (filed October 9, 1998), as amended
         on November 3, 1998.

         We will provide at no cost to each person to whom this prospectus is
delivered, upon written or oral request, a copy of any of these filings,
excluding the exhibits to such filings that we have not specifically
incorporated by reference in such filings. You should direct such requests to us
at 1601 Trapelo Road, Reservoir Place, Waltham, Massachusetts 02451, Attention:
Murray Fish, President and Chief Financial Officer, telephone number (781)
522-3400.

                                        2
<PAGE>

                    NOTE REGARDING FORWARD-LOOKING STATEMENTS

         This prospectus contains certain forward-looking statements within the
meaning of Section 27A of the Securities Act and Section 21E of the Exchange
Act. Forward-looking statements are statements that include information based
upon beliefs of our management, as well as assumptions made by and information
available to our management. Statements containing terms such as "believes,"
"expects," "anticipates," "intends" or similar words are intended to identify
forward-looking statements.

         Our management, based upon assumptions they consider reasonable, has
compiled these forward-looking statements. Such statements reflect our current
views with respect to future events. These statements involve known and unknown
risks and uncertainties that may cause our actual results in future periods to
differ materially from what is currently anticipated. We make cautionary
statements in certain sections of this prospectus, including under "Risk
Factors." You should read these cautionary statements as being applicable to all
related forward-looking statements wherever they appear in this prospectus, the
materials referred to in this prospectus or the materials incorporated by
reference into this prospectus.

         You are cautioned that no forward-looking statement is a guarantee of
future performance and you should not place undue reliance on any
forward-looking statement. Such statements speak only as of the date of this
prospectus and we are not undertaking any obligation to publicly release any
revisions to these forward-looking statements to reflect events or circumstances
after the date of this prospectus or to reflect the occurrence of unanticipated
events.




























                                        3
<PAGE>
                                  RISK FACTORS

         THE SHARES OFFERED HEREBY ARE SPECULATIVE AND INVOLVE A HIGH DEGREE OF
RISK. YOU SHOULD CAREFULLY CONSIDER THE FOLLOWING RISK FACTORS BEFORE DECIDING
TO INVEST IN OUR COMMON STOCK.


         WE HAVE A HISTORY OF LOSSES AND IF WE DO NOT ACHIEVE PROFITABILITY, WE
MAY NOT BE ABLE TO CONTINUE OUR BUSINESS IN THE FUTURE.

         We have incurred substantial operating losses since our inception,
which has resulted in an accumulated deficit of $27,494,000 as of March 31, 2001
For the three months ended March 31, 2001, we incurred a net loss of $1,012,000.
For the years ended December 31, 2000 and 1999, we incurred net losses of
$4,789,000 and $6,946,000, respectively. We have financed our operations
primarily through the sales of equity and debt securities as well as the sale of
our professional services business in February 2000. Our expense levels are high
and our revenues are difficult to predict. We anticipate incurring additional
losses until we increase our client base and revenues. We may never achieve or
sustain significant revenues or profitability. If we are unable to achieve
increased revenues, we will continue to have losses and may not be able to
continue our operations.


         WE COULD BE REQUIRED TO CUT BACK OR STOP OPERATIONS IF WE ARE UNABLE TO
RAISE OR OBTAIN NEEDED FUNDING.

         Our ability to continue our current level of operations will depend on
our ability to raise additional funds through equity or debt financing no later
than December, 2001 (or earlier if the Company does not achieve certain revenue
assumptions). We are currently seeking financing. However, we currently do not
have any definitive arrangements with respect to obtaining additional financing
and we may not be able to obtain such financing on commercially reasonable
terms, if at all. Our failure to obtain financing by December, 2001, may cause
us to substantially curtail or ultimately cease our current level of operations.


         WE HAVE NOT ACHIEVED SUBSTANTIAL REVENUE FROM SOFTWARE SALES.

         We have made only limited sales of our products. Our total revenues for
software licenses for the three months ended March 31, 2001 were $396,000. Our
total revenues for software licenses for the years ended December 31, 2000 and
1999 were $978,000 and $260,000, respectively.


         THE SALE OF OUR PROFESSIONAL SERVICES BUSINESS WILL HAVE AN ADVERSE
EFFECT ON FUTURE CASH FLOW AND REVENUES.

         In February 2000, we sold our professional services business to Exodus
Communications Inc. for $3.815 million in cash. As part of the transaction with
Exodus, we agreed not to offer any professional or consulting services for two
(2) years following the closing. The professional services business accounted
for 77% and 62% of our total revenues during the fiscal years ended December 31,
1999 and 1998, respectively. Accordingly, cash flow from operations has been and
may continue to be materially adversely effected from the sale of our
professional services business until, if ever, we generate sufficient revenue
from the licensing of our software products.


         OUR REVENUES DEPEND ON SALES OF OUR CYBERWALLPLUS(TM) PRODUCTS AND WE
ARE UNCERTAIN WHETHER THERE WILL BE BROAD MARKET ACCEPTANCE OF THESE PRODUCTS.

         Our revenue growth for the foreseeable future is dependent upon
increased sales of our CYBERWALLPLUS(TM) family of software products. Since the
introduction of our predecessor line of security products (FireWall/Plus) in
June 1995 through March 31, 2001, license revenue from these software products
has been $4,296,000 including a non-refundable pre-paid royalty of $500,000 in
1997. Since the introduction of our

                                        4
<PAGE>
CYBERWALLPLUS(TM) suite of products in January 1999 through March 31, 2001,
license revenue from our CYBERWALLPLUS(TM) products was only $1,563,000. Our
future financial performance will depend upon the successful introduction and
customer acceptance of our CYBERWALLPLUS(TM) products as well as the development
of new and enhanced versions of this product. Revenue from products such as
CYBERWALLPLUS(TM) depend on a number of factors, including the influence of
market competition, technological changes in the network security market, our
ability to design, develop and introduce enhancements on a timely basis and our
ability to successfully establish and maintain distribution channels. If we fail
to achieve broad market acceptance of our CYBERWALLPLUS(TM) products, it would
have a material adverse effect on our business, operating results and financial
condition.

         OUR INABILITY TO ENTER INTO STRATEGIC RELATIONSHIPS WITH INDIRECT
CHANNEL PARTNERS COULD HAVE A MATERIAL ADVERSE EFFECT ON US.

         As part of our sales and marketing efforts, we are seeking to develop
strategic relationships with indirect channel partners, such as original
equipment manufacturers and resellers. We have limited financial, personnel and
other resources to undertake extensive marketing activities ourselves.
Therefore, our prospects will depend on our ability to develop and maintain
strategic marketing relationships with indirect channel partners and their
ability to market and distribute our products. If we are unable to enter into
and maintain such arrangements or if such arrangements do not result in the
successful commercialization of our products, then this could have a material
adverse effect on our business, operating results and financial condition.

         WE MAY NOT BE ABLE TO SUCCESSFULLY COMPETE IN THE NETWORK SECURITY
MARKET.

         The network security market is characterized by intense competition and
rapidly changing business conditions, customer requirements and technologies.
The principal competitive factors affecting the market for network security
products include security effectiveness, scope of product offerings, name
recognition, product features, distribution channels, price, ease of use and
customer service and support. Most of our current and potential competitors have
longer operating histories, greater name recognition, larger installed customer
bases and possess substantially greater financial, technical and marketing and
other competitive resources than us. As a result, our competitors may be able to
adapt more quickly to new or emerging technologies and changes in customer
requirements or to devote greater resources to the promotion and sale of their
products than we may. In addition, certain of our competitors may determine for
strategic reasons to consolidate, to substantially lower the price of their
network security products or to bundle their products with other products, such
as hardware or other enterprise software products. Our current and potential
competitors may develop products that may be more effective than our current or
future products or that render our products obsolete or less marketable.
Increased competition for network security products may result in price
reductions and reduced gross margins and may adversely effect our ability to
gain market share, any of which would adversely affect our business, operating
results and financial condition.

         OUR OPERATING RESULTS MAY FLUCTUATE QUARTERLY AND IF THEY WERE BELOW
THE EXPECTATIONS OF INVESTORS AND ANALYSTS, THE PRICE OF OUR STOCK WOULD LIKELY
BE ADVERSELY EFFECTED.

         We anticipate significant quarterly fluctuations in our operations in
the future, since our results are dependent on the volume and timing of orders,
which are difficult to predict. Customers' purchasing patterns and budgeting
cycles, as well as the introduction of new products, may also cause our
operating results to fluctuate. Therefore, comparing quarterly operating results
may not be meaningful and should not be relied on. Also, our operating results
may be below the markets expectations in some future quarters, which would
likely have a material adverse effect on our common stock's price.

                                        5
<PAGE>

         WE NEED TO ATTRACT AND RETAIN A QUALIFIED CHIEF EXECUTIVE OFFICER AS
WELL AS OTHER QUALIFIED TECHNICAL, SALES, MARKETING DEVELOPMENT AND OTHER
MANAGEMENT PERSONNEL.

         On June 12, 2001, Avi Fogel resigned as our Chief Executive Officer,
President and a Director. Murray Fish, our Chief Financial Officer, is serving
as acting President. We are conducting a search for a new Chief Executive
Officer. If we are unable to hire and retain a qualified Chief Executive
Officer, our business, operating results and financial condition could be
materially adversely affected.

         Our success will also depend on our ability to attract, train and
retain highly qualified technical, sales, marketing, development and other
managerial personnel. There is considerable and often intense competition for
the services of such personnel. We may not be able either to retain our existing
personnel or acquire additional qualified personnel as and when needed. If we
are unable to hire and retain such personnel, our business, operating results
and financial condition could be materially adversely affected.

         WE MAY NOT BE ABLE TO ADEQUATELY PROTECT OUR PROPRIETARY TECHNOLOGY,
WHICH COULD RESULT IN LOWER REVENUES AND/OR PROFITS.

         We do not hold any patents and rely on copyright and trade secret laws,
non-disclosure agreements and contractual provisions to protect our proprietary
technology. These methods afford only limited protection. Despite the
precautions we take, unauthorized parties may attempt to copy or otherwise
obtain and use our proprietary technologies, ideas, know-how and other
proprietary information without authorization or may independently develop
technologies similar or superior to our technologies. Policing unauthorized use
of our products may be difficult and costly. Also, the laws of some foreign
countries do not protect our proprietary rights as much as the laws of the
United States. We are unable to predict whether our means of protecting our
proprietary rights will be adequate.

         We believe that our technologies have been developed independent of
others. Nevertheless, third parties may assert infringement claims against us
and our technologies may be determined to infringe on the intellectual property
rights of others. We could become liable for damages, be required to modify our
technologies or obtain a license if our technologies are determined to infringe
upon the intellectual property rights of others. We may not be able to modify
our technologies or obtain a license in a timely manner, if required, or have
the financial or other resources necessary to defend an infringement action. We
would be materially adversely effected if we fail to do any of the foregoing.

         WE CAN BE EXPOSED TO NUMEROUS POTENTIAL LIABILITY CLAIMS FOR DAMAGES
FROM THE USE OF OUR PRODUCTS AND, IF OUR INSURANCE DOESN'T ADEQUATELY COVER
LOSSES, THIS COULD HAVE A MATERIAL ADVERSE EFFECT ON US.

         Since our products are used to prevent unauthorized access to and
attacks on critical enterprise information, we may be exposed to potential
liability claims for damage caused as a result of an actual or alleged failure
of an installed product. We cannot assure you that the provisions in our
standard license agreements designed to limit our exposure will be enforceable.
Our personnel often gain access to confidential and proprietary client
information. Any unauthorized use or disclosure of such information could result
in a claim for substantial damages. We can give no assurances that our insurance
policies will be sufficient to cover potential claims or that adequate levels of
coverage will be available in the future at a reasonable cost.

         POSSIBLE DELISTING OF OUR SECURITIES FROM NASDAQ SYSTEM; RISKS RELATING
TO LOW-PRICED STOCKS.

         Our common stock is listed on the Nasdaq SmallCap Market under the
symbol "NSSI." In order to continue to be listed on Nasdaq, however, we must
comply with certain maintenance standards (including, among others, a minimum
stock price of $1.00 and net tangible assets of a minimum $2,000,000). In the
event of a delisting, an investor could find it more difficult to dispose of or
to obtain accurate quotations as to the market value of our common stock.

                                        6
<PAGE>
         In addition, if our common stock were to become delisted from trading
on Nasdaq and the trading price of our common stock were to then be below $5.00
per share, our common stock could be considered a penny stock. SEC regulations
generally define a penny stock to be an equity security that is not listed on
Nasdaq or a national securities exchange and that has a market value of less
than $5.00 per share, subject to certain exceptions. The SEC regulations would
require broker-dealers to deliver to a purchaser of our common stock a
disclosure schedule explaining the penny stock market and the risks associated
with it. Various sales practice requirements are also imposed on broker-dealers
who sell penny stocks to persons other than established customers and accredited
investors (generally institutions). Broker-dealers must also provide the
customer with current bid and offer quotations for the penny stock, the
compensation of the broker-dealer and monthly account statements disclosing
recent price information for the penny stock held in the customer's account. If
our common stock is no longer traded on Nasdaq and becomes subject to the
regulations applicable to penny stocks, investors may find it more difficult to
obtain timely and accurate quotes and execute trades in our common stock.


         THE SIGNIFICANT NUMBER OF OPTIONS, WARRANTS AND CONVERTIBLE SECURITIES
OUTSTANDING MAY ADVERSELY AFFECT THE MARKET PRICE FOR OUR COMMON STOCK.

         As of June 15, 2001, there are outstanding (i) options and warrants to
purchase an aggregate of 3,160,124 shares of our common stock at exercise prices
ranging from $1.00 to $10.125, (ii) 231,054 shares of Series D Convertible
Preferred Stock which are convertible at any time into an equal number of shares
of our common stock and (iii) debt in the principal amount of $300,000, which
can be converted into 98,360 shares of our Series D Preferred Stock (up to
114,098 shares if interest through the maturity of the promissory notes were
also converted into common stock at the same conversion price) and warrants to
purchase 98,360 shares of our common stock (up to 114,098 shares if you include
potential interest through the maturity of the promissory notes) at exercise
prices ranging from $1.00 to $3.00 per share. To the extent that outstanding
options, warrants or convertible debt are exercised or converted, your
percentage ownership will be diluted and any sales in the public market of the
common stock underlying such options, warrants or convertible debt may adversely
affect prevailing market prices for our common stock.


         WE HAVE A SIGNIFICANT AMOUNT OF AUTHORIZED BUT UNISSUED PREFERRED
STOCK, WHICH MAY AFFECT THE LIKELIHOOD OF A CHANGE OF CONTROL IN OUR COMPANY.

         As of the date of this Prospectus, our Board of Directors has the
authority, without further action by the stockholders, to issue 5,000,000 shares
of preferred stock (of which only 231,054 shares of Series D Preferred Stock are
outstanding as of the date hereof) on such terms and with such rights,
preferences and designations as the Board may determine. Such terms may include
restricting dividends on our common stock, dilution of the voting power of our
common stock or impairing the liquidation rights of the holders of our common
stock. Issuance of such preferred stock, depending on the rights, preferences
and designations thereof, may have the effect of delaying, deterring or
preventing a change in control. In addition, certain "anti-takeover" provisions
in Delaware law may restrict the ability of our stockholders to authorize a
merger, business combination or change of control.




                                        7
<PAGE>
                                   THE COMPANY

         We develop, market, license and support a family of network security
software products designed to provide comprehensive security to computer
networks, including Internet based systems and internal networks and computing
resources. Our CYBERWALLPLUS(TM) TM family of security software products enables
an organization to protect its computer networks from internal and external
attacks and to secure organizational communications over such internal networks
and the Internet. Our CYBERWALLPLUS(TM) suite of products was first introduced
in January 1999 and evolved from its prior FireWall/Plus suite of security
software products. We also offered our customers a full range of consulting
services in network security and network design through our professional
services group prior to its sale to Exodus Communications, Inc. in February
2000.

         The CYBERWALLPLUS(TM) family of security solutions is designed to
protect against Internet and Intranet based security threats and to address
security needs that arise from within internal networks that often utilize other
network transport protocols besides TCP/IP (the Internet network transport
protocol) including, among others, Novell's IPX, Digital Equipment's DECnet and
IBM's SNA. Our CYBERWALLPLUS(TM) family of network security products operates on
tHE Microsoft Windows NT and Windows 2000 operating system platforms. The filter
engine software technology of CYBERWALLPLUS(TM) , with its ability to handle and
filter all commonly used network transport protocols, provides organizations
with a highly secure and flexible security solution. Additionally, unlike most
firewall solutions which focus on an enterprise's connection to the Internet,
the CYBERWALLPLUS(TM) solution can be deployed throughout the enterprise; at the
perimeter to control access to and from the Internet, between internal networks
and on application servers and desktop PCs.

         Every day, more and more companies are turning to e-Business and
extranets as a way to obtain a competitive edge and broaden their markets. The
e-Business revolution is helping companies reduce costs, increase responsiveness
and provide empowerment through immediate knowledge. However, by tying together
previous separate company networks and inviting customers, partners and
suppliers onto their networks, companies have found that what were once closed
and secure enterprise networks are now becoming open networks.

         Within these new open networks, the traditional perimeters and network
boundaries have disappeared. We do not believe traditional perimeter security
devices such as firewalls can effectively secure all of a network's resources
which have embraced e-Business. Our CYBERWALLPLUS(TM) family of products is
designed to solve this problem BY protecting data where it resides - between the
internal sub networks and inside the server itself - finally allowing
organizations to leverage the promise of electronic business, while ensuring the
safety of strategic data assets.

         Key elements of our strategy are to:

         o    Focus on securing e-Business networks by replacing perimeter
              "chokepoint" firewalls with our web server embedded firewalls and
              intrusion prevention software (CYBERWALLPLUS(TM) - SV);

         o    Emphasize the need for internal network security to secure
              e-Business networks. Internal network security is an important
              element of an effective multi-layer defense strategy to protect
              against external attacks, as the CSI/FBI 2000 Computer Security
              study indicates that approximately 33% of the organizations with
              perimeter firewalls were breached by outsiders. In addition,
              Internal network security is critical to protect enterprise
              resources from unwelcomed "insider" access. The same CSI/FBI 2000
              study found that 79% of all breaches were from those with
              "insider" access; and

         o    Implement a sales plan that includes a multi-channel distribution
              strategy, emphasizing selling direct to end customers and
              establishing and maintaining third-party resale relationships with
              OEMs, systems integrators and VARs in the United States and
              internationally.

         We were incorporated under the laws of the State of Delaware in July
1990. Our executive offices are located at 1601 Trapelo Road, Reservoir Place,
Waltham, Massachusetts 02451 and our telephone number is (781) 522-3400. Our web
site can be found at http://www.network-1.com.

                                        8
<PAGE>


                                 USE OF PROCEEDS

         The shares of common stock offered hereby are being registered for the
account of the selling stockholders identified in this prospectus. See "Selling
Stockholders." All net proceeds from the sale of the common stock will go to the
stockholders who offer and sell their shares. We will not receive any part of
the proceeds from such sales of common stock. We will, however, receive the
exercise price of the options at the time of their exercise. Such proceeds will
be contributed to working capital and will be used for general corporate
purposes.












































                                        9
<PAGE>
                              SELLING STOCKHOLDERS
         This prospectus relates to the reoffer and resale of shares issued or
that may be issued to the selling stockholders under our Stock Option Plan. The
following table sets forth (i) the number of shares of common stock beneficially
owned by each selling stockholder as of the date of this prospectus, (ii) the
number of shares to be offered for resale by each selling stockholder (i.e., the
total number of shares underlying options held by each selling stockholder
irrespective of whether such options are presently exercisable or exercisable
within sixty days of the date of this prospectus), and (iii) the number and
percentage of shares of our common stock to be held by each selling stockholder
after completion of the offering.
<TABLE><CAPTION>
                                 NUMBER OF SHARES
                                 OF COMMON STOCK     NUMBER OF           NUMBER OF SHARES      PERCENTAGE OF
                                 BENEFICIALLY        SHARES OF           OF COMMON STOCK       OUTSTANDING
                                 OWNED PRIOR TO      COMMON STOCK        BENEFICIALLY OWNED    COMMON STOCK
NAME                             OFFERING(1)         BEING OFFERED(2)    AFTER OFFERING(3)     AFTER OFFERING(4)
-----                            ----------------    ----------------    ------------------    -----------------
<S>                              <C>                 <C>                 <C>                   <C>
Barry Rubenstein                   1,887,765 (5)        59,375 (6)           1,840,265              27.6%
   Wheatley Partners II, L.P.
   Woodland Venture Fund
   Seneca Ventures
   Woodland Partners

Irwin Lieber                       1,384,481 (7)        59,375 (8)           1,336,981              20.9%
   Wheatley Partners II, L.P.

Corey M. Horowitz                    896,991 (9)        53,125 (10)            855,741              12.8%

CMH Capital Management Corp.

Avi A. Fogel                         522,423 (11)      325,725 (12)            361,236               5.3%

Murray P. Fish                        79,170 (13)      156,269 (14)                  0                 0

Joseph A. Donohue                     62,548 (15)      151,399 (16)                  0                 0

Emanuel R. Pearlman                   43,322 (17)       31,250 (18)             20,822                 *

Mark Tuomenoksa                       20,000 (19)       25,000 (20)                  0                 0

Jonathan Mark                         15,000 (21)       25,000 (22)                  0                 0
</TABLE>
------------------

*  Less than 1%

(1)  Unless otherwise indicated, we believe that all people named in the above
     table have sole voting and investment power with respect to all shares of
     common stock beneficially owned by them. A person is deemed to be the
     beneficial owner of securities that can be acquired by such person within
     60 days from the date hereof upon the exercise of options, warrants or
     convertible securities. Each beneficial owner's percentage ownership is
     determined by assuming that options, warrants and convertible securities
     held by such person (but not those held by any other person) and which are
     exercisable or convertible within 60 days have been exercised or converted.

                                       10
<PAGE>

(2)  Consists of shares issuable upon the exercise of options both currently
     exercisable and not currently exercisable.

(3)  Beneficial ownership of shares held by each selling stockholder after this
     offering assumes that each selling stockholder sold all of the shares it is
     offering in this prospectus but actually will depend on the number of
     shares sold by such selling stockholder in this offering.

(4)  Assumes a base of 6,467,458 shares of common stock outstanding.

(5)  Includes (i) 31,040 shares of common stock held by Mr. Rubenstein, (ii)
     47,500 shares of common stock subject to currently exercisable stock
     options held by Mr. Rubenstein, (iii) 50,159 shares of common stock subject
     to currently exercisable warrants held by Mr. Rubenstein, (iv) 1,194,659,
     151,628 and 133,780 shares of common stock held by Wheatley Partners II,
     L.P., Woodland Venture Fund and Seneca Ventures, respectively, (v) 69,379,
     34,689, 34,689 and 495 shares of common stock subject to currently
     exercisable warrants held by Woodland Venture Fund, Seneca Ventures,
     Woodland Partners and Marilyn Rubenstein, respectively, and (vi) 69,379,
     34,689, 34,689, 495 and 495 shares of common stock issuable upon conversion
     of Series D Preferred Stock held by Woodland Venture Fund, Seneca Ventures,
     Woodland Partners, Barry Rubenstein and Marilyn Rubenstein, respectively.
     Barry Rubenstein is a general partner of Wheatley Partners II, L.P. Barry
     Rubenstein and Woodland Services Corp. are the general partners of Woodland
     Venture Fund and Seneca Ventures. Barry Rubenstein is the President and
     sole director of Woodland Services Corp. Barry Rubenstein is the general
     partner of Woodland Partners. Marilyn Rubenstein is the wife of Barry
     Rubenstein. Mr. Rubenstein disclaims beneficial ownership of the shares of
     common stock held by Wheatley Partners II, L.P., except to the extent of
     his equity interest therein. Does not include 11,875 shares of common stock
     subject to stock options which are not currently exercisable.

(6)  Includes 47,500 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 11,875 shares of
     common stock subject to stock options not currently exercisable held by Mr.
     Rubenstein.

(7)  Includes (i) 23,280 shares of common stock held by Mr. Lieber, (ii) 47,500
     shares of common stock subject to currently exercisable stock options held
     by Mr. Lieber, (iii) 84,353 shares of common stock subject to currently
     exercisable warrants held by Mr. Lieber, (iv) 1,194,659 shares of common
     stock held by Wheatley Partners II, L.P., and (v) 34,689 shares of common
     stock issuable upon conversion of Series D Preferred Stock held by Mr.
     Lieber. Irwin Lieber is a general partner of Wheatley Partners II, L.P. Mr.
     Lieber disclaims beneficial ownership of the shares of common stock held by
     Wheatley Partners II, L.P., except to the extent of his equity interest
     therein. Does not include 11,875 shares of common stock subject to stock
     options which are not currently exercisable.

(8)  Includes 47,500 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 11,875 shares of
     common stock subject to stock options not currently exercisable held by Mr.
     Lieber.

(9)  Includes (i) 486,303 shares of common stock held by Mr. Horowitz, (ii)
     41,250 shares of common stock subject to currently exercisable stock
     options held by Mr. Horowitz, (iii) 155,463 shares of common stock held by
     CMH Capital Management Corp. ("CMH"), (iv) 124,936 shares of common stock
     subject to currently exercisable warrants held by CMH, (v) 85,220 shares of
     common stock subject to currently exercisable warrants held by Mr.
     Horowitz, (vi) 2,291 shares of Common Stock held by Horowitz Partners, a
     general partnership of which Mr. Horowitz is a partner and (vii) 1,528
     shares of Common Stock held by Donna Slavitt, Mr. Horowitz' wife. Does not
     include 11,875 shares of common stock subject to stock options which are
     not currently exercisable. The address of CMH Capital Management Corp. is
     885 Third Avenue, New York, New York 10022.

(10) Includes 41,250 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 11,875 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Horowitz.

                                       11
<PAGE>

(11) Includes (i) 49,700 shares of Common Stock owned by Mr. Fogel, (ii) 456,066
     shares of common stock subject to currently exercisable stock options and
     (iii) 16,657 shares of common stock subject to currently exercisable
     warrants. Does not include 164,538 shares subject to stock options which
     are not currently exercisable.

(12) Includes 161,187 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 164,538 shares
     of common stock subject to stock options not currently exercisable, held by
     Mr. Fogel.

(13) Includes 79,170 shares of Common Stock subject to currently exercisable
     stock options issued to Mr. Fish pursuant to the Stock Option Plan. Does
     not include 77,099 shares of Common Stock subject to stock options which
     are not currently exercisable.

(14) Includes 79,170 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 77,099 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Fish.

(15) Includes 62,548 shares of Common Stock subject to currently exercisable
     stock options issued to Mr. Donohue pursuant to the Stock Option Plan. Does
     not include 88,851 shares of Common Stock subject to stock options which
     are not currently exercisable.

(16) Includes 62,548 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 88,851 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Donohue.

(17) Includes (i) 4,430 shares of Common Stock owned by an entity controlled by
     Mr. Pearlman, (ii) 22,500 shares of common stock subject to currently
     exercisable options issued to Mr. Pearlman pursuant to the Stock Option
     Plan, (ii) 4,098 shares of common stock subject to currently exercisable
     warrants, (iii) 4,098 shares of common stock issuable upon conversion of
     Series D Preferred, (iv) 4,098 shares of common stock subject to currently
     exercisable warrants underlying certain promissory notes and (v) 4,098
     shares of common stock issuable upon conversion of Series D Preferred Stock
     underlying certain promissory notes. Does not include 8,750 shares of
     common stock subject to options not currently exercisable.

(18) Includes 22,500 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 8,750 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Pearlman.

(19) Includes 20,000 shares of Common Stock subject to currently exercisable
     options issued to Mr. Tuomenoksa. Does not include 5,000 shares of Common
     Stock subject to options not currently exercisable.

(20) Includes 20,000 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 5,000 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Tuomenoksa.

(21) Includes 15,000 shares of Common Stock subject to currently exercisable
     options issued to Mr. Mark. Does not include 10,000 shares of Common Stock
     subject to options not currently exercisable.

(22) Includes 15,000 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 10,000 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Mark.



                                       12
<PAGE>

                              PLAN OF DISTRIBUTION

         This offering is self-underwritten. Neither the selling stockholders
nor we have employed an underwriter for the sale of common stock by the selling
stockholders. We will bear all expenses in connection with the preparation of
this Prospectus. The selling stockholders will bear all expenses associated with
the sale of the common stock.

         At the time a selling stockholder makes an offer to sell shares, to the
extent required by the Securities Act, a prospectus will be delivered. If a
supplemental prospectus is required, one will be delivered setting forth the
number of shares being offered and the terms of the offering.

         The selling stockholders may sell the shares in transactions in the
over-the-counter market, in negotiated transactions, or a combination of such
methods of sale. The selling stockholders may sell the shares through public or
private transactions at prevailing market prices, at prices related to such
prevailing market prices or at privately negotiated prices. The selling
stockholders may also sell shares pursuant to Rule 144 of the Securities Act, if
applicable. There can be no assurance that the selling stockholders will sell
any or all of the shares offered by them hereunder or otherwise.

         The selling stockholders may use broker-dealers to sell the shares.
Such broker-dealers may receive compensation in the form of discounts,
concessions or commissions from the selling stockholders, or they may receive
commissions from the purchasers of shares for whom they acted as agents, or both
(which compensation as to a particular broker-dealer might be in excess of
customary commissions). The selling stockholders and any broker-dealer who
participates in the distribution of the shares may be deemed to be
"underwriters" within the meaning of the Securities Act, and any commissions
received by them and any profit on the resale of the shares purchased by them
may be deemed to be underwriting discounts or commissions under the Securities
Act. Any such commissions, as well as other expenses incurred by the selling
stockholders and applicable transfer taxes, are payable by the selling
stockholders.

         The selling stockholders reserve the right to accept, and together with
any agent of the selling stockholder, to reject, in whole or in part, any
proposed purchase of the shares of common stock. The selling stockholders will
pay any sales commissions or other seller's compensation applicable to such
transactions.

         We have not registered or qualified offers and sales of shares of the
common stock under the laws of any country, other than the United States. To
comply with certain states' securities laws, if applicable, the selling
stockholders will offer and sell their shares of common stock in such
jurisdictions only through registered or licensed brokers or dealers. In
addition, in certain states the selling stockholders may not offer or sell
shares of common stock unless we have registered or qualified such shares for
sale in such states or we have complied with an available exemption from
registration or qualification.

         The selling stockholders have represented to us that any purchase or
sale of shares of common stock by them will comply with Regulation M promulgated
under the Exchange Act. In general, Rule 102 under Regulation M prohibits any
person connected with a distribution of our common stock (a "Distribution") from
directly or indirectly bidding for, or purchasing for any account in which he or
she has a beneficial interest, any of our common stock or any right to purchase
our common stock, for a period of one business day before and after completion
of his or her participation in the distribution (we refer to that time period as
the "Distribution Period").

         During the Distribution Period, Rule 104 under Regulation M prohibits
the selling stockholders and any other persons engaged in the Distribution from
engaging in any stabilizing bid or purchasing our common stock except for the
purpose of preventing or retarding a decline in the open market price of our
common stock. No such person may effect any stabilizing transaction to
facilitate any offering at the market. Inasmuch as the selling stockholders will
be reoffering and reselling our common stock at the market, Rule 104 prohibits
them from effecting any stabilizing transaction in contravention of Rule 104
with respect to our common stock.

                                       13
<PAGE>
                                  LEGAL MATTERS

         The validity of the shares of common stock offered hereby have been
passed upon for us by Olshan Grundman Frome Rosenzweig & Wolosky LLP, 505 Park
Avenue, New York, New York 10022. Sam Schwartz, a member of that firm, owns
warrants and options to purchase 14,828 shares of our common stock as of the
date of this prospectus.


                                     EXPERTS

         The financial statements incorporated in this prospectus by reference
to the Annual Report on Form 10-KSB for the year ended December 31, 2000 have
been so incorporated in reliance on the report of Richard A. Eisner & Company,
LLP, independent accountants, given on the authority of said firm as experts in
auditing and accounting.


              DISCLOSURE OF COMMISSION POSITION ON INDEMNIFICATION
                         FOR SECURITIES ACT LIABILITIES

         Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to our directors, officers or persons controlling us, we
have been advised that it is the SEC's opinion that such indemnification is
against public policy as expressed in the Securities Act and is, therefore,
unenforceable.






























                                       14
<PAGE>







                       NETWORK-1 SECURITY SOLUTIONS, INC.


                                 886,518 SHARES
                                       OF
                                  COMMON STOCK


                               ------------------

                                   PROSPECTUS

                                -----------------



                                  June 28, 2001



<PAGE>
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

         The following documents filed by Network-1 Security Solutions, Inc.
(the "Company") with the Securities and Exchange Commission (the "Commission")
pursuant to the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), and the Securities Act of 1933, as amended (the "Securities Act"), are
incorporated by reference in, and made a part of, this Registration Statement:

         1)  Our Report on Form 8-K filed with the SEC on June 15, 2001;

         2)  Our Quarterly Report on Form 10-QSB for the quarterly period ended
             March 31, 2001;

         3)  Our Annual Report on Form 10-KSB for the year ended December 31,
             2000; and

         4)  The description of our common stock incorporated by reference in
             our Registration Statement on Form 8-A (filed October 9, 1998), as
             amended on November 3, 1998.

         All documents subsequently filed by the Company pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment that indicates that all shares of Common Stock offered
hereby have been sold or which deregisters all shares then remaining unsold,
shall be deemed to be incorporated by reference in this Registration Statement
and to be a part hereof from the date of filing of such documents. Any statement
contained in a document incorporated or deemed to be incorporated by reference
herein shall be deemed to be modified or superseded for purposes of this
Registration Statement to the extent that a statement contained herein or in any
other subsequently filed document which also is incorporated or deemed to be
incorporated by reference herein modifies or supersedes such statement. Any
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of this Registration Statement.


ITEM 4.  DESCRIPTION OF SECURITIES

         Not applicable.


ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

         Not applicable.


ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporations Law (the "DGCL")
contains provisions entitling the Company's directors and officers to
indemnification from judgments, fines, amounts paid in settlement, and
reasonable expenses (including attorneys' fees) as the result of an action or
proceeding in which they may be involved by reason of having been a director or
officer of the Company. In its Certificate of Incorporation, the Company has
included a provision that limits, to the fullest extent now or hereafter
permitted by the DGCL, the personal liability of its directors to the Company or
its stockholders for monetary damages arising from a breach of their fiduciary
duties as directors. Under the DGCL as currently in effect, this provision
limits a director's liability except where such director (i) breaches his duty
of loyalty to the Company or its stockholders, (ii) fails to act in good faith
or engages in intentional misconduct

                                      II-1
<PAGE>
or a knowing violation of law, (iii) authorizes payment of an unlawful dividend
or stock purchase or redemption as provided in Section 174 of the DGCL, or (iv)
obtains an improper personal benefit. This provision does not prevent the
Company or its stockholders from seeking equitable remedies, such as injunctive
relief or rescission. If equitable remedies are found not to be available to
stockholders in any particular case, stockholders may not have any effective
remedy against actions taken by directors that constitute negligence or gross
negligence.

         The Certificate of Incorporation also includes provisions to the effect
that (subject to certain exceptions) the Company shall, to the maximum extent
permitted from time to time under the law of the State of Delaware, indemnify,
and upon request shall advance expenses to, any director or officer to the
extent that such indemnification and advancement of expenses is permitted under
such law, as it may from time to time be in effect. In addition, the Bylaws
require the Company to indemnify, to the full extent permitted by law, any
director, office, employee or agent of the Company for acts which such person
reasonably believes are not in violation of the Company's corporate purposes as
set forth in the Certificate of Incorporation. At present, the DGCL provides
that, in order to be entitled to indemnification, an individual must have acted
in good faith and in a manner he or she reasonably believed to be in or not
opposed to the Company's best interests.

         Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
Company pursuant to any charter, provision, by-law, contract, arrangement,
statute or otherwise, the Company has been advised that in the opinion of the
SEC such indemnification is against public policy as expressed in the Securities
Act and is, therefore, unenforceable.


ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

         Not applicable.


ITEM 8.  EXHIBITS

 No.     Description
 ---     -----------

 4.1     Certificate of Incorporation, as amended, of the Company. Previously
         filed as Exhibit 3.1 to the Company's Registration Statement on Form
         SB-2 (Registration No. 333-59617), declared effective by the Commission
         on November 12, 1998 (the "1998 Registration Statement"), and
         incorporated herein by reference.

 4.2     By-laws of the Company. Previously filed as Exhibit 3.2 to the 1998
         Registration Statement, and incorporated herein by reference.

 4.3     The Company's Amended and Restated 1996 Stock Option Plan. Previously
         filed as an attachment to the Company's Proxy Statement filed on
         October 6, 2000, and incorporated herein by reference.

 5*      Opinion of Olshan Grundman Frome Rosenzweig & Wolosky LLP regarding
         legality of securities being registered.

 23.1*   Consent of Richard A. Eisner & Company, LLP, independent certified
         public accountants.

 23.2*   Consent of Olshan Grundman Frome Rosenzweig & Wolosky LLP (contained in
         Exhibit 5).

 24*     Powers of Attorney (included on signature page to this Registration
         Statement).

--------------
 *  Filed herewith

                                      II-2
<PAGE>

ITEM 9.  UNDERTAKINGS.

         (a)  The undersigned Registrant hereby undertakes that it will:

                  (1)   File, during any period in which it offers or sells
                        securities, a post-effective amendment to this
                        Registration Statement to include any additional or
                        changed material information on the plan of
                        distribution.

                  (2)   For determining liability under the Securities Act,
                        treat each post-effective amendment as a new
                        Registration Statement of the securities offered, and
                        the offering of securities at that time to be the
                        initial bona fide offering.

                  (3)   File a post-effective amendment to remove from
                        registration any of the securities that remain unsold at
                        the end of this offering.

         (b) Insofar as indemnification for liabilities arising under the
Securities Act 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 and is, therefore, unenforceable.




























                                      II-3
<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 Waltham, Commonwealth of Massachusetts.

Dated: June 28, 2001                 NETWORK-1 SECURITY SOLUTIONS, INC.

                                     By:  /s/ Murray P. Fish
                                          -------------------------------------
                                          Murray P. Fish
                                          President and Chief Financial Officer


                                POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS, that each director and officer whose
signature appears below constitutes and appoints Murray P. Fish, or any of them,
his true and lawful attorney-in-fact and agent, with full power and substitution
and re-substitution, to sign in any and all capacities any and all amendments or
post-effective amendments to this Registration Statement on Form S-8 and to file
the same with all exhibits thereto and other documents in connection therewith
with the Securities and Exchange Commission, granting to such attorneys-in-fact
and agents, and each of them, full power and authority to do all such other acts
and execute all such other documents as they, or any of them, may deem necessary
or desirable in connection with the foregoing, as fully as the undersigned might
or could do in person, hereby ratifying and confirming all that such
attorneys-in-fact and agents, or any of them, 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 and on the dates indicated:

Signature                Title                                    Date
---------                -----                                    ----

/s/ Murray P. Fish       President, Chief Financial Officer and   June 28, 2001
---------------------    Director (principal executive officer
Murray P. Fish           and principal financial and accounting
                         officer)


/s/ Corey M. Horowitz    Chairman of the Board of Directors       June 28, 2001
---------------------
Corey M. Horowitz


/s/ Jonathan Mark        Director                                 June 28, 2001
---------------------
Jonathan Mark

                                      II-4
<PAGE>


                                INDEX TO EXHIBITS


NO.      DESCRIPTION
---      -----------

 4.1     Certificate of Incorporation, as amended, of the Company. Previously
         filed as Exhibit 3.1 to the Company's Registration Statement on Form
         SB-2 (Registration No. 333-59617), declared effective by the Commission
         on November 12, 1998 (the "1998 Registration Statement"), and
         incorporated herein by reference.

 4.2     By-laws of the Company. Previously filed as Exhibit 3.2 to the 1998
         Registration Statement, and incorporated herein by reference.

 4.3     The Company's Amended and Restated 1996 Stock Option Plan. Previously
         filed as an attachment to the Company's Proxy Statement filed on
         October 6, 2000, and incorporated herein by reference.

 5*      Opinion of Olshan Grundman Frome Rosenzweig & Wolosky, LLP regarding
         legality of securities being registered.

 23.1*   Consent of Richard A. Eisner & Company, LLP, independent certified
         public accountants.

 23.2*   Consent of Olshan Grundman Frome Rosenzweig & Wolosky LLP (contained in
         Exhibit 5).

 24*     Powers of Attorney (included on signature page to this Registration
         Statement).

--------------
    *    Filed herewith
















                                      II-5
[{"type": "S-8", "sequence": "1", "filename": "forms-8_10712.txt", "description": "FORM S-8", "secsgml_size_bytes": 67317}]
{"company-data": {"conformed-name": "NETWORK 1 SECURITY SOLUTIONS INC", "cik": "0001065078", "assigned-sic": "7372", "irs-number": "113027591", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-64066", "film-number": "1670402"}, "business-address": {"street1": "1601 TRAPELO RD", "street2": "RESERVOIR PLACE", "city": "WALTHAM", "state": "MA", "zip": "02451", "phone": "7815223400"}, "mail-address": {"street1": "1601 TRAPELO RD", "street2": "RESERVOIR PLACE", "city": "WALTHAM", "state": "MA", "zip": "02451"}}
As filed with the Securities and Exchange Commission on June 28, 2001
                                               REGISTRATION NO. 333-_______
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                               ------------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                              ---------------------

                       NETWORK-1 SECURITY SOLUTIONS, INC.
             (Exact name of registrant as specified in its charter)

           DELAWARE                                             11-3027591
(State or other jurisdiction                                 (I.R.S. employer
     of incorporation)                                    identification number)

                       1601 TRAPELO ROAD, RESERVOIR PLACE
                          WALTHAM, MASSACHUSETTS 02451
                                 (781) 522-3400
    (Address, including zip code, and telephone number, including area code,
                  of Registrant's principal executive offices)

                             ----------------------

                       NETWORK-1 SECURITY SOLUTIONS, INC.
                   AMENDED AND RESTATED 1996 STOCK OPTION PLAN
                            (Full title of the plan)

                             ----------------------

                                 MURRAY P. FISH
                      PRESIDENT AND CHIEF FINANCIAL OFFICER
                       NETWORK-1 SECURITY SOLUTIONS, INC.
                       1601 TRAPELO ROAD, RESERVOIR PLACE
                          WALTHAM, MASSACHUSETTS 02451
                                 (781) 522-3400
               (Address, including zip code, and telephone number,
                   including area code, of agent for service)

                             -----------------------

                                   COPIES TO:
                               SAM SCHWARTZ, ESQ.
                 OLSHAN GRUNDMAN FROME ROSENZWEIG & WOLOSKY LLP
                                 505 PARK AVENUE
                            NEW YORK, NEW YORK 10022
                                 (212) 753-7200

================================================================================
CALCULATION OF REGISTRATION FEE
===========================================  =================  ==============  ==================  ============
                                                                   PROPOSED
                                                                   MAXIMUM       PROPOSED MAXIMUM     AMOUNT OF
                                                AMOUNT TO BE    OFFERING PRICE  AGGREGATE OFFERING  REGISTRATION
TITLE OF SECURITIES TO BE REGISTERED         REGISTERED (1)(2)   PER SHARE (3)       PRICE (3)          FEE
-------------------------------------------  -----------------  --------------  ------------------  ------------
Common Stock, par value $.01 per share.....    735,000 shares      $1.71          $1,258,432          $314.61
===========================================  =================  ==============  ==================  ============
(1)  Represents the aggregate number of shares of common stock, par value $.01
     per share (the "Common Stock"), of Network-1 Security Solutions, Inc. (the
     "Company") issuable upon exercise of stock options granted or to be granted
     by the Company under its Amended and Restated 1996 Stock Option Plan, as
     amended and restated to date (the "Plan"), for which no registration
     statement has been filed. A registration statement (Registration No.
     333-93895) covering the other 1,800,000 shares of Common Stock issuable
     upon exercise of stock options granted under the Plan was filed on December
     30, 1999.

(2)  Pursuant to Rule 416, this registration statement also covers such
     indeterminate additional shares of Common Stock as may become issuable as a
     result of any future anti-dilution adjustment in accordance with the terms
     of the Plan.

(3)  Pursuant to Rule 457(h) promulgated under the Securities Act, includes (i)
     an aggregate of 244,268 shares with respect to which options have been
     granted under the Plan at an average exercise price of $ 3.0625 and (ii) an
     additional 490,732 shares which may be offered under the Plan at a price,
     based on the average of the high and low sales prices for the shares of
     Common Stock as reported on The Nasdaq Stock Market's SmallCap Market on
     June 26, 2001, of $1.04.
EXPLANATORY NOTES

         On December 30, 1999, Network-1 Security Solutions, Inc. (the
"Company") filed a Registration Statement on Form S-8 (Registration No.
333-93895) registering 1,800,000 shares of the Company's common stock, par value
$.01 per share (the "Common Stock"), issuable upon exercise of stock options
granted by the Company under its Amended and Restated 1996 Stock Option Plan, as
amended and restated as of such date (the "Plan"). The Company has prepared this
Registration Statement in accordance with the requirements of Form S-8 under the
Securities Act of 1933, as amended (the "Securities Act"), to register the
735,000 additional shares of Common Stock issuable upon exercise of stock
options that have been added to the Plan.

         This Form S-8 includes a Reoffer Prospectus prepared in accordance with
Part I of Form S-3 under the Securities Act. The Reoffer Prospectus may be
utilized for reofferings and resales of shares of Common Stock acquired pursuant
to the Plan by selling stockholders who may be deemed "affiliates" (as such term
is defined in Rule 405 under the Securities Act) of the Company. Some of these
shares were previously registered.

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS

         The Company will provide documents containing the information specified
in Part 1 of Form S-8 to employees as specified by Rule 428(b)(1) under the
Securities Act. Pursuant to the instructions to Form S-8, the Company is not
required to file these documents either as part of this Registration Statement
or as prospectuses or prospectus supplements pursuant to Rule 424 under the
Securities Act.
PROSPECTUS

                                 886,518 SHARES
                       NETWORK-1 SECURITY SOLUTIONS, INC.
                          COMMON STOCK ($.01 PAR VALUE)

         This prospectus relates to the reoffer and resale by certain selling
stockholders of shares of our common stock that may be issued by us to the
selling stockholders upon the exercise of stock options granted under our Stock
Option Plan. We previously registered the offer and sale of the shares to the
selling stockholders. This prospectus also relates to certain underlying options
that have not as of this date been granted. If and when such options are granted
to persons required to use this prospectus to reoffer and resell the shares
underlying such options, we will distribute a prospectus supplement. The shares
are being reoffered and resold for the account of the selling stockholders and
we will not receive any of the proceeds from the resale of the shares.

         The selling stockholders have advised us that the resale of their
shares may be effected from time to time in one or more transactions on The
Nasdaq Stock Market's SmallCap Market, in negotiated transactions or otherwise,
at market prices prevailing at the time of the sale or at prices otherwise
negotiated. See "Plan of Distribution." We will bear all expenses in connection
with the preparation of this prospectus.

         Our common stock is listed on The Nasdaq Stock Market's SmallCap
Market. On June 26, 2001, the closing price for our Common Stock, as reported by
the Nasdaq SmallCap Market, was $1.04.

THE SECURITIES OFFERED IN THIS PROSPECTUS INVOLVE A HIGH DEGREE OF RISK. YOU
SHOULD CAREFULLY CONSIDER THE FACTORS DESCRIBED UNDER THE HEADING "RISK FACTORS"
BEGINNING ON PAGE 4 OF THIS PROSPECTUS.

--------------------------------------------------------------------------------

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

--------------------------------------------------------------------------------

                  THE DATE OF THIS PROSPECTUS IS JUNE 28, 2001.
TABLE OF CONTENTS

                                                                            PAGE
                                                                            ----

ABOUT THIS PROSPECTUS.......................................................  2

WHERE YOU CAN FIND MORE INFORMATION.........................................  2

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.............................  2

NOTE REGARDING FORWARD-LOOKING STATEMENTS...................................  3

RISK FACTORS................................................................  4

THE COMPANY.................................................................  8

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

SELLING STOCKHOLDERS........................................................ 10

PLAN OF DISTRIBUTION........................................................ 13

LEGAL MATTERS............................................................... 14

EXPERTS..................................................................... 14

DISCLOSURE OF COMMISSION POSITION ON........................................ 14

INDEMNIFICATION FOR SECURITIES ACT LIABILITIES.............................. 14

                                        i
ABOUT THIS PROSPECTUS

         This prospectus is part of a registration statement we filed with the
Securities and Exchange Commission (the "SEC") and therefore omits certain
information in such registration statement. We have also filed exhibits with the
registration statement that are not included in this prospectus, and you should
refer to the applicable exhibit for a complete description of any statement
referring to any document. You can inspect a copy of the registration statement
and its exhibits, without charge, at the SEC's public reference room, and can
copy such material upon paying the SEC's prescribed rates.

         You should rely only on the information and representations provided or
incorporated by reference in this prospectus or any related supplement. We have
not authorized anyone else to provide you with different information. The
Selling Stockholders will not make an offer of these shares in any state where
the offer is not permitted. You should not assume that the information in this
prospectus or any supplement is accurate as of any date other than the date on
the front of those documents.

                       WHERE YOU CAN FIND MORE INFORMATION

         We file annual, quarterly and special reports, proxy statements and
other information with the SEC. You may read and copy any document we file at
the SEC's public reference room located at Judiciary Plaza, 450 Fifth Street,
N.W., Washington, D.C. 20549. The SEC has prescribed rates for copying. You may
obtain further information on the operation of the public reference room by
calling the SEC at 1-800-SEC-0330. Our SEC filings are also available to the
public over the Internet at the SEC's web site at http://www.sec.gov.

                 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

         The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents. The information we incorporate by reference is
considered to be a part of this prospectus and information that we file later
with the SEC will automatically update and replace the information in this
prospectus. Accordingly, we incorporate by reference the documents listed below
and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or
15(d) of the Securities Exchange Act of 1934, as amended:

     1.  Our Report on Form 8-K filed with the SEC on June 15, 2001;

     2.  Our Quarterly Report on Form 10-QSB for the quarterly period ended
         March 31, 2001;

     3.  Our Annual Report on Form 10-KSB for the year ended December 31, 2000;
         and

     4.  The description of our common stock incorporated by reference in our
         Registration Statement on Form 8-A (filed October 9, 1998), as amended
         on November 3, 1998.

         We will provide at no cost to each person to whom this prospectus is
delivered, upon written or oral request, a copy of any of these filings,
excluding the exhibits to such filings that we have not specifically
incorporated by reference in such filings. You should direct such requests to us
at 1601 Trapelo Road, Reservoir Place, Waltham, Massachusetts 02451, Attention:
Murray Fish, President and Chief Financial Officer, telephone number (781)
522-3400.

                                        2
NOTE REGARDING FORWARD-LOOKING STATEMENTS

         This prospectus contains certain forward-looking statements within the
meaning of Section 27A of the Securities Act and Section 21E of the Exchange
Act. Forward-looking statements are statements that include information based
upon beliefs of our management, as well as assumptions made by and information
available to our management. Statements containing terms such as "believes,"
"expects," "anticipates," "intends" or similar words are intended to identify
forward-looking statements.

         Our management, based upon assumptions they consider reasonable, has
compiled these forward-looking statements. Such statements reflect our current
views with respect to future events. These statements involve known and unknown
risks and uncertainties that may cause our actual results in future periods to
differ materially from what is currently anticipated. We make cautionary
statements in certain sections of this prospectus, including under "Risk
Factors." You should read these cautionary statements as being applicable to all
related forward-looking statements wherever they appear in this prospectus, the
materials referred to in this prospectus or the materials incorporated by
reference into this prospectus.

         You are cautioned that no forward-looking statement is a guarantee of
future performance and you should not place undue reliance on any
forward-looking statement. Such statements speak only as of the date of this
prospectus and we are not undertaking any obligation to publicly release any
revisions to these forward-looking statements to reflect events or circumstances
after the date of this prospectus or to reflect the occurrence of unanticipated
events.

                                        3
RISK FACTORS

         THE SHARES OFFERED HEREBY ARE SPECULATIVE AND INVOLVE A HIGH DEGREE OF
RISK. YOU SHOULD CAREFULLY CONSIDER THE FOLLOWING RISK FACTORS BEFORE DECIDING
TO INVEST IN OUR COMMON STOCK.

         WE HAVE A HISTORY OF LOSSES AND IF WE DO NOT ACHIEVE PROFITABILITY, WE
MAY NOT BE ABLE TO CONTINUE OUR BUSINESS IN THE FUTURE.

         We have incurred substantial operating losses since our inception,
which has resulted in an accumulated deficit of $27,494,000 as of March 31, 2001
For the three months ended March 31, 2001, we incurred a net loss of $1,012,000.
For the years ended December 31, 2000 and 1999, we incurred net losses of
$4,789,000 and $6,946,000, respectively. We have financed our operations
primarily through the sales of equity and debt securities as well as the sale of
our professional services business in February 2000. Our expense levels are high
and our revenues are difficult to predict. We anticipate incurring additional
losses until we increase our client base and revenues. We may never achieve or
sustain significant revenues or profitability. If we are unable to achieve
increased revenues, we will continue to have losses and may not be able to
continue our operations.

         WE COULD BE REQUIRED TO CUT BACK OR STOP OPERATIONS IF WE ARE UNABLE TO
RAISE OR OBTAIN NEEDED FUNDING.

         Our ability to continue our current level of operations will depend on
our ability to raise additional funds through equity or debt financing no later
than December, 2001 (or earlier if the Company does not achieve certain revenue
assumptions). We are currently seeking financing. However, we currently do not
have any definitive arrangements with respect to obtaining additional financing
and we may not be able to obtain such financing on commercially reasonable
terms, if at all. Our failure to obtain financing by December, 2001, may cause
us to substantially curtail or ultimately cease our current level of operations.

         WE HAVE NOT ACHIEVED SUBSTANTIAL REVENUE FROM SOFTWARE SALES.

         We have made only limited sales of our products. Our total revenues for
software licenses for the three months ended March 31, 2001 were $396,000. Our
total revenues for software licenses for the years ended December 31, 2000 and
1999 were $978,000 and $260,000, respectively.

         THE SALE OF OUR PROFESSIONAL SERVICES BUSINESS WILL HAVE AN ADVERSE
EFFECT ON FUTURE CASH FLOW AND REVENUES.

         In February 2000, we sold our professional services business to Exodus
Communications Inc. for $3.815 million in cash. As part of the transaction with
Exodus, we agreed not to offer any professional or consulting services for two
(2) years following the closing. The professional services business accounted
for 77% and 62% of our total revenues during the fiscal years ended December 31,
1999 and 1998, respectively. Accordingly, cash flow from operations has been and
may continue to be materially adversely effected from the sale of our
professional services business until, if ever, we generate sufficient revenue
from the licensing of our software products.

         OUR REVENUES DEPEND ON SALES OF OUR CYBERWALLPLUS(TM) PRODUCTS AND WE
ARE UNCERTAIN WHETHER THERE WILL BE BROAD MARKET ACCEPTANCE OF THESE PRODUCTS.

         Our revenue growth for the foreseeable future is dependent upon
increased sales of our CYBERWALLPLUS(TM) family of software products. Since the
introduction of our predecessor line of security products (FireWall/Plus) in
June 1995 through March 31, 2001, license revenue from these software products
has been $4,296,000 including a non-refundable pre-paid royalty of $500,000 in
1997. Since the introduction of our

                                        4
CYBERWALLPLUS(TM) suite of products in January 1999 through March 31, 2001,
license revenue from our CYBERWALLPLUS(TM) products was only $1,563,000. Our
future financial performance will depend upon the successful introduction and
customer acceptance of our CYBERWALLPLUS(TM) products as well as the development
of new and enhanced versions of this product. Revenue from products such as
CYBERWALLPLUS(TM) depend on a number of factors, including the influence of
market competition, technological changes in the network security market, our
ability to design, develop and introduce enhancements on a timely basis and our
ability to successfully establish and maintain distribution channels. If we fail
to achieve broad market acceptance of our CYBERWALLPLUS(TM) products, it would
have a material adverse effect on our business, operating results and financial
condition.

         OUR INABILITY TO ENTER INTO STRATEGIC RELATIONSHIPS WITH INDIRECT
CHANNEL PARTNERS COULD HAVE A MATERIAL ADVERSE EFFECT ON US.

         As part of our sales and marketing efforts, we are seeking to develop
strategic relationships with indirect channel partners, such as original
equipment manufacturers and resellers. We have limited financial, personnel and
other resources to undertake extensive marketing activities ourselves.
Therefore, our prospects will depend on our ability to develop and maintain
strategic marketing relationships with indirect channel partners and their
ability to market and distribute our products. If we are unable to enter into
and maintain such arrangements or if such arrangements do not result in the
successful commercialization of our products, then this could have a material
adverse effect on our business, operating results and financial condition.

         WE MAY NOT BE ABLE TO SUCCESSFULLY COMPETE IN THE NETWORK SECURITY
MARKET.

         The network security market is characterized by intense competition and
rapidly changing business conditions, customer requirements and technologies.
The principal competitive factors affecting the market for network security
products include security effectiveness, scope of product offerings, name
recognition, product features, distribution channels, price, ease of use and
customer service and support. Most of our current and potential competitors have
longer operating histories, greater name recognition, larger installed customer
bases and possess substantially greater financial, technical and marketing and
other competitive resources than us. As a result, our competitors may be able to
adapt more quickly to new or emerging technologies and changes in customer
requirements or to devote greater resources to the promotion and sale of their
products than we may. In addition, certain of our competitors may determine for
strategic reasons to consolidate, to substantially lower the price of their
network security products or to bundle their products with other products, such
as hardware or other enterprise software products. Our current and potential
competitors may develop products that may be more effective than our current or
future products or that render our products obsolete or less marketable.
Increased competition for network security products may result in price
reductions and reduced gross margins and may adversely effect our ability to
gain market share, any of which would adversely affect our business, operating
results and financial condition.

         OUR OPERATING RESULTS MAY FLUCTUATE QUARTERLY AND IF THEY WERE BELOW
THE EXPECTATIONS OF INVESTORS AND ANALYSTS, THE PRICE OF OUR STOCK WOULD LIKELY
BE ADVERSELY EFFECTED.

         We anticipate significant quarterly fluctuations in our operations in
the future, since our results are dependent on the volume and timing of orders,
which are difficult to predict. Customers' purchasing patterns and budgeting
cycles, as well as the introduction of new products, may also cause our
operating results to fluctuate. Therefore, comparing quarterly operating results
may not be meaningful and should not be relied on. Also, our operating results
may be below the markets expectations in some future quarters, which would
likely have a material adverse effect on our common stock's price.

                                        5
WE NEED TO ATTRACT AND RETAIN A QUALIFIED CHIEF EXECUTIVE OFFICER AS
WELL AS OTHER QUALIFIED TECHNICAL, SALES, MARKETING DEVELOPMENT AND OTHER
MANAGEMENT PERSONNEL.

         On June 12, 2001, Avi Fogel resigned as our Chief Executive Officer,
President and a Director. Murray Fish, our Chief Financial Officer, is serving
as acting President. We are conducting a search for a new Chief Executive
Officer. If we are unable to hire and retain a qualified Chief Executive
Officer, our business, operating results and financial condition could be
materially adversely affected.

         Our success will also depend on our ability to attract, train and
retain highly qualified technical, sales, marketing, development and other
managerial personnel. There is considerable and often intense competition for
the services of such personnel. We may not be able either to retain our existing
personnel or acquire additional qualified personnel as and when needed. If we
are unable to hire and retain such personnel, our business, operating results
and financial condition could be materially adversely affected.

         WE MAY NOT BE ABLE TO ADEQUATELY PROTECT OUR PROPRIETARY TECHNOLOGY,
WHICH COULD RESULT IN LOWER REVENUES AND/OR PROFITS.

         We do not hold any patents and rely on copyright and trade secret laws,
non-disclosure agreements and contractual provisions to protect our proprietary
technology. These methods afford only limited protection. Despite the
precautions we take, unauthorized parties may attempt to copy or otherwise
obtain and use our proprietary technologies, ideas, know-how and other
proprietary information without authorization or may independently develop
technologies similar or superior to our technologies. Policing unauthorized use
of our products may be difficult and costly. Also, the laws of some foreign
countries do not protect our proprietary rights as much as the laws of the
United States. We are unable to predict whether our means of protecting our
proprietary rights will be adequate.

         We believe that our technologies have been developed independent of
others. Nevertheless, third parties may assert infringement claims against us
and our technologies may be determined to infringe on the intellectual property
rights of others. We could become liable for damages, be required to modify our
technologies or obtain a license if our technologies are determined to infringe
upon the intellectual property rights of others. We may not be able to modify
our technologies or obtain a license in a timely manner, if required, or have
the financial or other resources necessary to defend an infringement action. We
would be materially adversely effected if we fail to do any of the foregoing.

         WE CAN BE EXPOSED TO NUMEROUS POTENTIAL LIABILITY CLAIMS FOR DAMAGES
FROM THE USE OF OUR PRODUCTS AND, IF OUR INSURANCE DOESN'T ADEQUATELY COVER
LOSSES, THIS COULD HAVE A MATERIAL ADVERSE EFFECT ON US.

         Since our products are used to prevent unauthorized access to and
attacks on critical enterprise information, we may be exposed to potential
liability claims for damage caused as a result of an actual or alleged failure
of an installed product. We cannot assure you that the provisions in our
standard license agreements designed to limit our exposure will be enforceable.
Our personnel often gain access to confidential and proprietary client
information. Any unauthorized use or disclosure of such information could result
in a claim for substantial damages. We can give no assurances that our insurance
policies will be sufficient to cover potential claims or that adequate levels of
coverage will be available in the future at a reasonable cost.

         POSSIBLE DELISTING OF OUR SECURITIES FROM NASDAQ SYSTEM; RISKS RELATING
TO LOW-PRICED STOCKS.

         Our common stock is listed on the Nasdaq SmallCap Market under the
symbol "NSSI." In order to continue to be listed on Nasdaq, however, we must
comply with certain maintenance standards (including, among others, a minimum
stock price of $1.00 and net tangible assets of a minimum $2,000,000). In the
event of a delisting, an investor could find it more difficult to dispose of or
to obtain accurate quotations as to the market value of our common stock.

                                        6
In addition, if our common stock were to become delisted from trading
on Nasdaq and the trading price of our common stock were to then be below $5.00
per share, our common stock could be considered a penny stock. SEC regulations
generally define a penny stock to be an equity security that is not listed on
Nasdaq or a national securities exchange and that has a market value of less
than $5.00 per share, subject to certain exceptions. The SEC regulations would
require broker-dealers to deliver to a purchaser of our common stock a
disclosure schedule explaining the penny stock market and the risks associated
with it. Various sales practice requirements are also imposed on broker-dealers
who sell penny stocks to persons other than established customers and accredited
investors (generally institutions). Broker-dealers must also provide the
customer with current bid and offer quotations for the penny stock, the
compensation of the broker-dealer and monthly account statements disclosing
recent price information for the penny stock held in the customer's account. If
our common stock is no longer traded on Nasdaq and becomes subject to the
regulations applicable to penny stocks, investors may find it more difficult to
obtain timely and accurate quotes and execute trades in our common stock.

         THE SIGNIFICANT NUMBER OF OPTIONS, WARRANTS AND CONVERTIBLE SECURITIES
OUTSTANDING MAY ADVERSELY AFFECT THE MARKET PRICE FOR OUR COMMON STOCK.

         As of June 15, 2001, there are outstanding (i) options and warrants to
purchase an aggregate of 3,160,124 shares of our common stock at exercise prices
ranging from $1.00 to $10.125, (ii) 231,054 shares of Series D Convertible
Preferred Stock which are convertible at any time into an equal number of shares
of our common stock and (iii) debt in the principal amount of $300,000, which
can be converted into 98,360 shares of our Series D Preferred Stock (up to
114,098 shares if interest through the maturity of the promissory notes were
also converted into common stock at the same conversion price) and warrants to
purchase 98,360 shares of our common stock (up to 114,098 shares if you include
potential interest through the maturity of the promissory notes) at exercise
prices ranging from $1.00 to $3.00 per share. To the extent that outstanding
options, warrants or convertible debt are exercised or converted, your
percentage ownership will be diluted and any sales in the public market of the
common stock underlying such options, warrants or convertible debt may adversely
affect prevailing market prices for our common stock.

         WE HAVE A SIGNIFICANT AMOUNT OF AUTHORIZED BUT UNISSUED PREFERRED
STOCK, WHICH MAY AFFECT THE LIKELIHOOD OF A CHANGE OF CONTROL IN OUR COMPANY.

         As of the date of this Prospectus, our Board of Directors has the
authority, without further action by the stockholders, to issue 5,000,000 shares
of preferred stock (of which only 231,054 shares of Series D Preferred Stock are
outstanding as of the date hereof) on such terms and with such rights,
preferences and designations as the Board may determine. Such terms may include
restricting dividends on our common stock, dilution of the voting power of our
common stock or impairing the liquidation rights of the holders of our common
stock. Issuance of such preferred stock, depending on the rights, preferences
and designations thereof, may have the effect of delaying, deterring or
preventing a change in control. In addition, certain "anti-takeover" provisions
in Delaware law may restrict the ability of our stockholders to authorize a
merger, business combination or change of control.

                                        7
THE COMPANY

         We develop, market, license and support a family of network security
software products designed to provide comprehensive security to computer
networks, including Internet based systems and internal networks and computing
resources. Our CYBERWALLPLUS(TM) TM family of security software products enables
an organization to protect its computer networks from internal and external
attacks and to secure organizational communications over such internal networks
and the Internet. Our CYBERWALLPLUS(TM) suite of products was first introduced
in January 1999 and evolved from its prior FireWall/Plus suite of security
software products. We also offered our customers a full range of consulting
services in network security and network design through our professional
services group prior to its sale to Exodus Communications, Inc. in February
2000.

         The CYBERWALLPLUS(TM) family of security solutions is designed to
protect against Internet and Intranet based security threats and to address
security needs that arise from within internal networks that often utilize other
network transport protocols besides TCP/IP (the Internet network transport
protocol) including, among others, Novell's IPX, Digital Equipment's DECnet and
IBM's SNA. Our CYBERWALLPLUS(TM) family of network security products operates on
tHE Microsoft Windows NT and Windows 2000 operating system platforms. The filter
engine software technology of CYBERWALLPLUS(TM) , with its ability to handle and
filter all commonly used network transport protocols, provides organizations
with a highly secure and flexible security solution. Additionally, unlike most
firewall solutions which focus on an enterprise's connection to the Internet,
the CYBERWALLPLUS(TM) solution can be deployed throughout the enterprise; at the
perimeter to control access to and from the Internet, between internal networks
and on application servers and desktop PCs.

         Every day, more and more companies are turning to e-Business and
extranets as a way to obtain a competitive edge and broaden their markets. The
e-Business revolution is helping companies reduce costs, increase responsiveness
and provide empowerment through immediate knowledge. However, by tying together
previous separate company networks and inviting customers, partners and
suppliers onto their networks, companies have found that what were once closed
and secure enterprise networks are now becoming open networks.

         Within these new open networks, the traditional perimeters and network
boundaries have disappeared. We do not believe traditional perimeter security
devices such as firewalls can effectively secure all of a network's resources
which have embraced e-Business. Our CYBERWALLPLUS(TM) family of products is
designed to solve this problem BY protecting data where it resides - between the
internal sub networks and inside the server itself - finally allowing
organizations to leverage the promise of electronic business, while ensuring the
safety of strategic data assets.

         Key elements of our strategy are to:

         o    Focus on securing e-Business networks by replacing perimeter
              "chokepoint" firewalls with our web server embedded firewalls and
              intrusion prevention software (CYBERWALLPLUS(TM) - SV);

         o    Emphasize the need for internal network security to secure
              e-Business networks. Internal network security is an important
              element of an effective multi-layer defense strategy to protect
              against external attacks, as the CSI/FBI 2000 Computer Security
              study indicates that approximately 33% of the organizations with
              perimeter firewalls were breached by outsiders. In addition,
              Internal network security is critical to protect enterprise
              resources from unwelcomed "insider" access. The same CSI/FBI 2000
              study found that 79% of all breaches were from those with
              "insider" access; and

         o    Implement a sales plan that includes a multi-channel distribution
              strategy, emphasizing selling direct to end customers and
              establishing and maintaining third-party resale relationships with
              OEMs, systems integrators and VARs in the United States and
              internationally.

         We were incorporated under the laws of the State of Delaware in July
1990. Our executive offices are located at 1601 Trapelo Road, Reservoir Place,
Waltham, Massachusetts 02451 and our telephone number is (781) 522-3400. Our web
site can be found at http://www.network-1.com.

                                        8
USE OF PROCEEDS

         The shares of common stock offered hereby are being registered for the
account of the selling stockholders identified in this prospectus. See "Selling
Stockholders." All net proceeds from the sale of the common stock will go to the
stockholders who offer and sell their shares. We will not receive any part of
the proceeds from such sales of common stock. We will, however, receive the
exercise price of the options at the time of their exercise. Such proceeds will
be contributed to working capital and will be used for general corporate
purposes.

                                        9
SELLING STOCKHOLDERS
         This prospectus relates to the reoffer and resale of shares issued or
that may be issued to the selling stockholders under our Stock Option Plan. The
following table sets forth (i) the number of shares of common stock beneficially
owned by each selling stockholder as of the date of this prospectus, (ii) the
number of shares to be offered for resale by each selling stockholder (i.e., the
total number of shares underlying options held by each selling stockholder
irrespective of whether such options are presently exercisable or exercisable
within sixty days of the date of this prospectus), and (iii) the number and
percentage of shares of our common stock to be held by each selling stockholder
after completion of the offering.
NUMBER OF SHARES
                                 OF COMMON STOCK     NUMBER OF           NUMBER OF SHARES      PERCENTAGE OF
                                 BENEFICIALLY        SHARES OF           OF COMMON STOCK       OUTSTANDING
                                 OWNED PRIOR TO      COMMON STOCK        BENEFICIALLY OWNED    COMMON STOCK
NAME                             OFFERING(1)         BEING OFFERED(2)    AFTER OFFERING(3)     AFTER OFFERING(4)
-----                            ----------------    ----------------    ------------------    -----------------
Barry Rubenstein                   1,887,765 (5)        59,375 (6)           1,840,265              27.6%
   Wheatley Partners II, L.P.
   Woodland Venture Fund
   Seneca Ventures
   Woodland Partners

Irwin Lieber                       1,384,481 (7)        59,375 (8)           1,336,981              20.9%
   Wheatley Partners II, L.P.

Corey M. Horowitz                    896,991 (9)        53,125 (10)            855,741              12.8%

CMH Capital Management Corp.

Avi A. Fogel                         522,423 (11)      325,725 (12)            361,236               5.3%

Murray P. Fish                        79,170 (13)      156,269 (14)                  0                 0

Joseph A. Donohue                     62,548 (15)      151,399 (16)                  0                 0

Emanuel R. Pearlman                   43,322 (17)       31,250 (18)             20,822                 *

Mark Tuomenoksa                       20,000 (19)       25,000 (20)                  0                 0

Jonathan Mark                         15,000 (21)       25,000 (22)                  0                 0
------------------

*  Less than 1%

(1)  Unless otherwise indicated, we believe that all people named in the above
     table have sole voting and investment power with respect to all shares of
     common stock beneficially owned by them. A person is deemed to be the
     beneficial owner of securities that can be acquired by such person within
     60 days from the date hereof upon the exercise of options, warrants or
     convertible securities. Each beneficial owner's percentage ownership is
     determined by assuming that options, warrants and convertible securities
     held by such person (but not those held by any other person) and which are
     exercisable or convertible within 60 days have been exercised or converted.

                                       10
(2)  Consists of shares issuable upon the exercise of options both currently
     exercisable and not currently exercisable.

(3)  Beneficial ownership of shares held by each selling stockholder after this
     offering assumes that each selling stockholder sold all of the shares it is
     offering in this prospectus but actually will depend on the number of
     shares sold by such selling stockholder in this offering.

(4)  Assumes a base of 6,467,458 shares of common stock outstanding.

(5)  Includes (i) 31,040 shares of common stock held by Mr. Rubenstein, (ii)
     47,500 shares of common stock subject to currently exercisable stock
     options held by Mr. Rubenstein, (iii) 50,159 shares of common stock subject
     to currently exercisable warrants held by Mr. Rubenstein, (iv) 1,194,659,
     151,628 and 133,780 shares of common stock held by Wheatley Partners II,
     L.P., Woodland Venture Fund and Seneca Ventures, respectively, (v) 69,379,
     34,689, 34,689 and 495 shares of common stock subject to currently
     exercisable warrants held by Woodland Venture Fund, Seneca Ventures,
     Woodland Partners and Marilyn Rubenstein, respectively, and (vi) 69,379,
     34,689, 34,689, 495 and 495 shares of common stock issuable upon conversion
     of Series D Preferred Stock held by Woodland Venture Fund, Seneca Ventures,
     Woodland Partners, Barry Rubenstein and Marilyn Rubenstein, respectively.
     Barry Rubenstein is a general partner of Wheatley Partners II, L.P. Barry
     Rubenstein and Woodland Services Corp. are the general partners of Woodland
     Venture Fund and Seneca Ventures. Barry Rubenstein is the President and
     sole director of Woodland Services Corp. Barry Rubenstein is the general
     partner of Woodland Partners. Marilyn Rubenstein is the wife of Barry
     Rubenstein. Mr. Rubenstein disclaims beneficial ownership of the shares of
     common stock held by Wheatley Partners II, L.P., except to the extent of
     his equity interest therein. Does not include 11,875 shares of common stock
     subject to stock options which are not currently exercisable.

(6)  Includes 47,500 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 11,875 shares of
     common stock subject to stock options not currently exercisable held by Mr.
     Rubenstein.

(7)  Includes (i) 23,280 shares of common stock held by Mr. Lieber, (ii) 47,500
     shares of common stock subject to currently exercisable stock options held
     by Mr. Lieber, (iii) 84,353 shares of common stock subject to currently
     exercisable warrants held by Mr. Lieber, (iv) 1,194,659 shares of common
     stock held by Wheatley Partners II, L.P., and (v) 34,689 shares of common
     stock issuable upon conversion of Series D Preferred Stock held by Mr.
     Lieber. Irwin Lieber is a general partner of Wheatley Partners II, L.P. Mr.
     Lieber disclaims beneficial ownership of the shares of common stock held by
     Wheatley Partners II, L.P., except to the extent of his equity interest
     therein. Does not include 11,875 shares of common stock subject to stock
     options which are not currently exercisable.

(8)  Includes 47,500 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 11,875 shares of
     common stock subject to stock options not currently exercisable held by Mr.
     Lieber.

(9)  Includes (i) 486,303 shares of common stock held by Mr. Horowitz, (ii)
     41,250 shares of common stock subject to currently exercisable stock
     options held by Mr. Horowitz, (iii) 155,463 shares of common stock held by
     CMH Capital Management Corp. ("CMH"), (iv) 124,936 shares of common stock
     subject to currently exercisable warrants held by CMH, (v) 85,220 shares of
     common stock subject to currently exercisable warrants held by Mr.
     Horowitz, (vi) 2,291 shares of Common Stock held by Horowitz Partners, a
     general partnership of which Mr. Horowitz is a partner and (vii) 1,528
     shares of Common Stock held by Donna Slavitt, Mr. Horowitz' wife. Does not
     include 11,875 shares of common stock subject to stock options which are
     not currently exercisable. The address of CMH Capital Management Corp. is
     885 Third Avenue, New York, New York 10022.

(10) Includes 41,250 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 11,875 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Horowitz.

                                       11
(11) Includes (i) 49,700 shares of Common Stock owned by Mr. Fogel, (ii) 456,066
     shares of common stock subject to currently exercisable stock options and
     (iii) 16,657 shares of common stock subject to currently exercisable
     warrants. Does not include 164,538 shares subject to stock options which
     are not currently exercisable.

(12) Includes 161,187 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 164,538 shares
     of common stock subject to stock options not currently exercisable, held by
     Mr. Fogel.

(13) Includes 79,170 shares of Common Stock subject to currently exercisable
     stock options issued to Mr. Fish pursuant to the Stock Option Plan. Does
     not include 77,099 shares of Common Stock subject to stock options which
     are not currently exercisable.

(14) Includes 79,170 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 77,099 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Fish.

(15) Includes 62,548 shares of Common Stock subject to currently exercisable
     stock options issued to Mr. Donohue pursuant to the Stock Option Plan. Does
     not include 88,851 shares of Common Stock subject to stock options which
     are not currently exercisable.

(16) Includes 62,548 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 88,851 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Donohue.

(17) Includes (i) 4,430 shares of Common Stock owned by an entity controlled by
     Mr. Pearlman, (ii) 22,500 shares of common stock subject to currently
     exercisable options issued to Mr. Pearlman pursuant to the Stock Option
     Plan, (ii) 4,098 shares of common stock subject to currently exercisable
     warrants, (iii) 4,098 shares of common stock issuable upon conversion of
     Series D Preferred, (iv) 4,098 shares of common stock subject to currently
     exercisable warrants underlying certain promissory notes and (v) 4,098
     shares of common stock issuable upon conversion of Series D Preferred Stock
     underlying certain promissory notes. Does not include 8,750 shares of
     common stock subject to options not currently exercisable.

(18) Includes 22,500 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 8,750 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Pearlman.

(19) Includes 20,000 shares of Common Stock subject to currently exercisable
     options issued to Mr. Tuomenoksa. Does not include 5,000 shares of Common
     Stock subject to options not currently exercisable.

(20) Includes 20,000 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 5,000 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Tuomenoksa.

(21) Includes 15,000 shares of Common Stock subject to currently exercisable
     options issued to Mr. Mark. Does not include 10,000 shares of Common Stock
     subject to options not currently exercisable.

(22) Includes 15,000 shares of common stock subject to currently exercisable
     stock options issued pursuant to the Stock Option Plan and 10,000 shares of
     common stock subject to stock options not currently exercisable, held by
     Mr. Mark.

                                       12
PLAN OF DISTRIBUTION

         This offering is self-underwritten. Neither the selling stockholders
nor we have employed an underwriter for the sale of common stock by the selling
stockholders. We will bear all expenses in connection with the preparation of
this Prospectus. The selling stockholders will bear all expenses associated with
the sale of the common stock.

         At the time a selling stockholder makes an offer to sell shares, to the
extent required by the Securities Act, a prospectus will be delivered. If a
supplemental prospectus is required, one will be delivered setting forth the
number of shares being offered and the terms of the offering.

         The selling stockholders may sell the shares in transactions in the
over-the-counter market, in negotiated transactions, or a combination of such
methods of sale. The selling stockholders may sell the shares through public or
private transactions at prevailing market prices, at prices related to such
prevailing market prices or at privately negotiated prices. The selling
stockholders may also sell shares pursuant to Rule 144 of the Securities Act, if
applicable. There can be no assurance that the selling stockholders will sell
any or all of the shares offered by them hereunder or otherwise.

         The selling stockholders may use broker-dealers to sell the shares.
Such broker-dealers may receive compensation in the form of discounts,
concessions or commissions from the selling stockholders, or they may receive
commissions from the purchasers of shares for whom they acted as agents, or both
(which compensation as to a particular broker-dealer might be in excess of
customary commissions). The selling stockholders and any broker-dealer who
participates in the distribution of the shares may be deemed to be
"underwriters" within the meaning of the Securities Act, and any commissions
received by them and any profit on the resale of the shares purchased by them
may be deemed to be underwriting discounts or commissions under the Securities
Act. Any such commissions, as well as other expenses incurred by the selling
stockholders and applicable transfer taxes, are payable by the selling
stockholders.

         The selling stockholders reserve the right to accept, and together with
any agent of the selling stockholder, to reject, in whole or in part, any
proposed purchase of the shares of common stock. The selling stockholders will
pay any sales commissions or other seller's compensation applicable to such
transactions.

         We have not registered or qualified offers and sales of shares of the
common stock under the laws of any country, other than the United States. To
comply with certain states' securities laws, if applicable, the selling
stockholders will offer and sell their shares of common stock in such
jurisdictions only through registered or licensed brokers or dealers. In
addition, in certain states the selling stockholders may not offer or sell
shares of common stock unless we have registered or qualified such shares for
sale in such states or we have complied with an available exemption from
registration or qualification.

         The selling stockholders have represented to us that any purchase or
sale of shares of common stock by them will comply with Regulation M promulgated
under the Exchange Act. In general, Rule 102 under Regulation M prohibits any
person connected with a distribution of our common stock (a "Distribution") from
directly or indirectly bidding for, or purchasing for any account in which he or
she has a beneficial interest, any of our common stock or any right to purchase
our common stock, for a period of one business day before and after completion
of his or her participation in the distribution (we refer to that time period as
the "Distribution Period").

         During the Distribution Period, Rule 104 under Regulation M prohibits
the selling stockholders and any other persons engaged in the Distribution from
engaging in any stabilizing bid or purchasing our common stock except for the
purpose of preventing or retarding a decline in the open market price of our
common stock. No such person may effect any stabilizing transaction to
facilitate any offering at the market. Inasmuch as the selling stockholders will
be reoffering and reselling our common stock at the market, Rule 104 prohibits
them from effecting any stabilizing transaction in contravention of Rule 104
with respect to our common stock.

                                       13
LEGAL MATTERS

         The validity of the shares of common stock offered hereby have been
passed upon for us by Olshan Grundman Frome Rosenzweig & Wolosky LLP, 505 Park
Avenue, New York, New York 10022. Sam Schwartz, a member of that firm, owns
warrants and options to purchase 14,828 shares of our common stock as of the
date of this prospectus.

                                     EXPERTS

         The financial statements incorporated in this prospectus by reference
to the Annual Report on Form 10-KSB for the year ended December 31, 2000 have
been so incorporated in reliance on the report of Richard A. Eisner & Company,
LLP, independent accountants, given on the authority of said firm as experts in
auditing and accounting.

              DISCLOSURE OF COMMISSION POSITION ON INDEMNIFICATION
                         FOR SECURITIES ACT LIABILITIES

         Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to our directors, officers or persons controlling us, we
have been advised that it is the SEC's opinion that such indemnification is
against public policy as expressed in the Securities Act and is, therefore,
unenforceable.

                                       14
NETWORK-1 SECURITY SOLUTIONS, INC.

                                 886,518 SHARES
                                       OF
                                  COMMON STOCK

                               ------------------

                                   PROSPECTUS

                                -----------------

                                  June 28, 2001
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

         The following documents filed by Network-1 Security Solutions, Inc.
(the "Company") with the Securities and Exchange Commission (the "Commission")
pursuant to the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), and the Securities Act of 1933, as amended (the "Securities Act"), are
incorporated by reference in, and made a part of, this Registration Statement:

         1)  Our Report on Form 8-K filed with the SEC on June 15, 2001;

         2)  Our Quarterly Report on Form 10-QSB for the quarterly period ended
             March 31, 2001;

         3)  Our Annual Report on Form 10-KSB for the year ended December 31,
             2000; and

         4)  The description of our common stock incorporated by reference in
             our Registration Statement on Form 8-A (filed October 9, 1998), as
             amended on November 3, 1998.

         All documents subsequently filed by the Company pursuant to Sections
13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment that indicates that all shares of Common Stock offered
hereby have been sold or which deregisters all shares then remaining unsold,
shall be deemed to be incorporated by reference in this Registration Statement
and to be a part hereof from the date of filing of such documents. Any statement
contained in a document incorporated or deemed to be incorporated by reference
herein shall be deemed to be modified or superseded for purposes of this
Registration Statement to the extent that a statement contained herein or in any
other subsequently filed document which also is incorporated or deemed to be
incorporated by reference herein modifies or supersedes such statement. Any
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of this Registration Statement.

ITEM 4.  DESCRIPTION OF SECURITIES

         Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL

         Not applicable.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporations Law (the "DGCL")
contains provisions entitling the Company's directors and officers to
indemnification from judgments, fines, amounts paid in settlement, and
reasonable expenses (including attorneys' fees) as the result of an action or
proceeding in which they may be involved by reason of having been a director or
officer of the Company. In its Certificate of Incorporation, the Company has
included a provision that limits, to the fullest extent now or hereafter
permitted by the DGCL, the personal liability of its directors to the Company or
its stockholders for monetary damages arising from a breach of their fiduciary
duties as directors. Under the DGCL as currently in effect, this provision
limits a director's liability except where such director (i) breaches his duty
of loyalty to the Company or its stockholders, (ii) fails to act in good faith
or engages in intentional misconduct

                                      II-1
or a knowing violation of law, (iii) authorizes payment of an unlawful dividend
or stock purchase or redemption as provided in Section 174 of the DGCL, or (iv)
obtains an improper personal benefit. This provision does not prevent the
Company or its stockholders from seeking equitable remedies, such as injunctive
relief or rescission. If equitable remedies are found not to be available to
stockholders in any particular case, stockholders may not have any effective
remedy against actions taken by directors that constitute negligence or gross
negligence.

         The Certificate of Incorporation also includes provisions to the effect
that (subject to certain exceptions) the Company shall, to the maximum extent
permitted from time to time under the law of the State of Delaware, indemnify,
and upon request shall advance expenses to, any director or officer to the
extent that such indemnification and advancement of expenses is permitted under
such law, as it may from time to time be in effect. In addition, the Bylaws
require the Company to indemnify, to the full extent permitted by law, any
director, office, employee or agent of the Company for acts which such person
reasonably believes are not in violation of the Company's corporate purposes as
set forth in the Certificate of Incorporation. At present, the DGCL provides
that, in order to be entitled to indemnification, an individual must have acted
in good faith and in a manner he or she reasonably believed to be in or not
opposed to the Company's best interests.

         Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
Company pursuant to any charter, provision, by-law, contract, arrangement,
statute or otherwise, the Company has been advised that in the opinion of the
SEC such indemnification is against public policy as expressed in the Securities
Act and is, therefore, unenforceable.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

         Not applicable.

ITEM 8.  EXHIBITS

 No.     Description
 ---     -----------

 4.1     Certificate of Incorporation, as amended, of the Company. Previously
         filed as Exhibit 3.1 to the Company's Registration Statement on Form
         SB-2 (Registration No. 333-59617), declared effective by the Commission
         on November 12, 1998 (the "1998 Registration Statement"), and
         incorporated herein by reference.

 4.2     By-laws of the Company. Previously filed as Exhibit 3.2 to the 1998
         Registration Statement, and incorporated herein by reference.

 4.3     The Company's Amended and Restated 1996 Stock Option Plan. Previously
         filed as an attachment to the Company's Proxy Statement filed on
         October 6, 2000, and incorporated herein by reference.

 5*      Opinion of Olshan Grundman Frome Rosenzweig & Wolosky LLP regarding
         legality of securities being registered.

 23.1*   Consent of Richard A. Eisner & Company, LLP, independent certified
         public accountants.

 23.2*   Consent of Olshan Grundman Frome Rosenzweig & Wolosky LLP (contained in
         Exhibit 5).

 24*     Powers of Attorney (included on signature page to this Registration
         Statement).

--------------
 *  Filed herewith

                                      II-2
ITEM 9.  UNDERTAKINGS.

         (a)  The undersigned Registrant hereby undertakes that it will:

                  (1)   File, during any period in which it offers or sells
                        securities, a post-effective amendment to this
                        Registration Statement to include any additional or
                        changed material information on the plan of
                        distribution.

                  (2)   For determining liability under the Securities Act,
                        treat each post-effective amendment as a new
                        Registration Statement of the securities offered, and
                        the offering of securities at that time to be the
                        initial bona fide offering.

                  (3)   File a post-effective amendment to remove from
                        registration any of the securities that remain unsold at
                        the end of this offering.

         (b) Insofar as indemnification for liabilities arising under the
Securities Act 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 and is, therefore, unenforceable.

                                      II-3
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 Waltham, Commonwealth of Massachusetts.

Dated: June 28, 2001                 NETWORK-1 SECURITY SOLUTIONS, INC.

                                     By:  /s/ Murray P. Fish
                                          -------------------------------------
                                          Murray P. Fish
                                          President and Chief Financial Officer

                                POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS, that each director and officer whose
signature appears below constitutes and appoints Murray P. Fish, or any of them,
his true and lawful attorney-in-fact and agent, with full power and substitution
and re-substitution, to sign in any and all capacities any and all amendments or
post-effective amendments to this Registration Statement on Form S-8 and to file
the same with all exhibits thereto and other documents in connection therewith
with the Securities and Exchange Commission, granting to such attorneys-in-fact
and agents, and each of them, full power and authority to do all such other acts
and execute all such other documents as they, or any of them, may deem necessary
or desirable in connection with the foregoing, as fully as the undersigned might
or could do in person, hereby ratifying and confirming all that such
attorneys-in-fact and agents, or any of them, 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 and on the dates indicated:

Signature                Title                                    Date
---------                -----                                    ----

/s/ Murray P. Fish       President, Chief Financial Officer and   June 28, 2001
---------------------    Director (principal executive officer
Murray P. Fish           and principal financial and accounting
                         officer)

/s/ Corey M. Horowitz    Chairman of the Board of Directors       June 28, 2001
---------------------
Corey M. Horowitz

/s/ Jonathan Mark        Director                                 June 28, 2001
---------------------
Jonathan Mark

                                      II-4
INDEX TO EXHIBITS

NO.      DESCRIPTION
---      -----------

 4.1     Certificate of Incorporation, as amended, of the Company. Previously
         filed as Exhibit 3.1 to the Company's Registration Statement on Form
         SB-2 (Registration No. 333-59617), declared effective by the Commission
         on November 12, 1998 (the "1998 Registration Statement"), and
         incorporated herein by reference.

 4.2     By-laws of the Company. Previously filed as Exhibit 3.2 to the 1998
         Registration Statement, and incorporated herein by reference.

 4.3     The Company's Amended and Restated 1996 Stock Option Plan. Previously
         filed as an attachment to the Company's Proxy Statement filed on
         October 6, 2000, and incorporated herein by reference.

 5*      Opinion of Olshan Grundman Frome Rosenzweig & Wolosky, LLP regarding
         legality of securities being registered.

 23.1*   Consent of Richard A. Eisner & Company, LLP, independent certified
         public accountants.

 23.2*   Consent of Olshan Grundman Frome Rosenzweig & Wolosky LLP (contained in
         Exhibit 5).

 24*     Powers of Attorney (included on signature page to this Registration
         Statement).

--------------
    *    Filed herewith

                                      II-5