<PAGE>
 
   As filed with the Securities and Exchange Commission on December 16, 1996

                                                                Registration No.

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

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

                                   FORM S-8
                            REGISTRATION STATEMENT
                       Under The Securities Act of 1933

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

                           UNISOURCE WORLDWIDE, INC.
              (exact name of registrant as specified in charter)

           DELEWARE                                       13-5369500
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
 incorporation or organization)

                              825 Duportail Road
                        Wayne, Pennsylvania 19087-5589
              (Address of principal executive offices)(Zip Code)

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

                           UNISOURCE WORLDWIDE, INC.
                         PARTNERS' STOCK PURCHASE PLAN
                           (Full title of the Plan)

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

                                Hugh G. Moulton
           Executive Vice President and Chief Administrative Officer
                           Unisource Worldwide, Inc.
                              825 Duportail Road
                        Wayne, Pennsylvania 19087-5589
                    (Name and address of agent for service)

                                (610) 296-8000
         (Telephone number, including area code, of agent for service)

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

                        CALCULATION OF REGISTRATION FEE

<TABLE> 
<CAPTION> 
                                 Proposed      Proposed
                                 maximum       maximum
  Title of        Amount         offering      aggregate      Amount of
securities to     to be          price         offering      registration
be registered     registered     per unit      price             fee
--------------------------------------------------------------------------------
<S>               <C>            <C>           <C>              <C> 
Common Stock      1,000,000      $19.50(1)     $19,500,000      $5,909
$0.001 
par value

--------------------------------------------------------------------------------
</TABLE> 

(1)  Calculated in accordance with Rule 457 (c) and (h) based upon the December
     10, 1996 closing quotation for when-issued common stock on the New York
     Stock Exchange.

<PAGE>

                                    PART I
                                    ------
 
             INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1.  Plan Information
-------------------------

     A prospectus setting forth the information required by Part I of Form S-8 
will be sent or given to participants as specified by Rule 428(b)(1).

Item 2.  Registrant Information and Employee Plan Annual Information
--------------------------------------------------------------------

     The documents incorporated by reference in Item 3 of Part II of this Form 
S-8 are incorporated by reference in the Section 10(a) prospectus relating to 
this registration statement.  The foregoing documents and all other documents 
required to be delivered to employees pursuant to Rule 428(b) are available 
without charge, upon written or oral request, to Unisource Worldwide, Inc., 825 
Duportail Road, Wayne, PA 19087, Attn:  Corporate Communications Department 
(telephone number: (610) 296-8000).

                                    PART II
                                    -------

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference
------------------------------------------------

     The Registrant's Registration Statement on Form 10 (effective November 26, 
1996) is incorporated by reference by the Registrant and the Plan in this 
registration statement.

     All documents subsequently filed by the Registrant pursuant to Sections 
13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the 
filing of a post-effective amendment indicating that all securities offered
hereby have been sold or which deregisters all securities then remaining unsold,
shall be deemed to be incorporated by reference in this Registration Statement
and to be part thereof from the date of filing of such documents.

Item 4.  Description of Securities
----------------------------------

     Not Applicable.

Item 5.  Interests of Named Experts and Counsel
-----------------------------------------------

     Not applicable.
<PAGE>
 
Item 6. Indemnification of Directors and Officers
-------------------------------------------------

     The Delaware General Corporation Law (the "DGCL"), under which the 
Registrant is organized, provides that the Registrant may indemnify persons who 
incur certain liabilities or expenses by reason of such persons being or having 
been directors, officers or employees of the Registrant or serving or having 
served in such capacities or similar capacities at the Registrant's request for 
other corporations or entities. Pursuant to the DGCL, the Registrant has 
adopted, as part of its By-Laws, provisions whereby the Registrant shall 
indemnify such persons against such liabilities and expenses resulting from 
suits or other proceedings brought by third persons and against expenses 
resulting from suits or other proceedings brought in the right of the 
Registrant. No indemnification against expenses is to be made, however, in 
respect of (i) any breach of the director's duty of loyalty to the Registrant or
its stockholders, (ii) for acts or omissions not in good faith or which involve 
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the DGCL, relating to prohibited dividends, distributions and repurchases or 
redemptions of stock, or (iv) for any transaction for which the director derives
and improper personal benefit.

     As permitted by law, the Registrant has purchased liability insurance 
policies covering its directors and officers to provide protection where the law
does not allow the Registrant to indemnify a director or officer. The policies 
also provide coverage for indemnifiable expenses, including expenses related to 
claims arising under the Employment Retirement Income Security Act against a 
director or officer based upon an alleged breach of fiduciary duty or other 
wrongful act with respect to an employee benefit plan.

Item 7. Exemption from Registration Claimed
-------------------------------------------

     Not applicable.

Item 8. Exhibits
----------------

     (4)   Rights Agreement, between the Registrant and National City Bank, the
           form of which was filed as Exhibit 2.2 to the Registrant's
           Registration Statement on Form 10 (effective November 26, 1996), is
           incorporated herein by reference.

     (5)   Opinion of Morgan, Lewis & Bockius as to the validity of the 
           securities.

     (23)  Consent of Independent Auditors.

     (99)  Unisource Worldwide, Inc. Partners' Stock Purchase Plan.

<PAGE>
 
Item 9. Undertakings
--------------------

        (a)    The Registrant hereby undertakes:

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

                      (i)    To include any prospectus required by Section 
10(a)(3) of the Securities Act of 1933;

                      (ii)   To reflect in the prospectus any facts or events 
arising after the effective date of the registration statement (or the most 
recent post-effective amendment thereof) which, individually or in the 
aggregate, represent a fundamental change in the information set forth in the 
registration statement;

                      (iii)  To include any material information with respect to
the plan of distribution not previously disclosed in the registration statement 
or any material change to such information in the registration statement;

        Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
if the registration statement is on Form S-3 or Form S-8, and the information 
required to be included in a post-effective amendment by those paragraphs is 
contained in periodic reports filed by the Registrant pursuant to Section 13 or 
Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by 
reference in the registration statement.

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

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

        (b)    The Registrant hereby undertakes that, for purposes of 
determining any liability under the Securities Act of 1933, each filing of the 
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the 
Securities Exchange Act of 1934 (and, where applicable, each filing of an 
employee benefit plan's annual report pursuant to Section 15(d) of the 
Securities Exchange Act of 1934) that is incorporated by reference in the 
registration statement shall be deemed to be a new registration statement 
relating to the securities offered therein, and the offering of such securities 
at that time shall be deemed to be the initial bona fide offering thereof.
  
     
<PAGE>
 
     (c)    Insofar as indemnification for liabilities arising under the 
Securities Act of 1933 may be permitted to directors, officers and controlling 
persons of the Registrant pursuant to the foregoing provisions, or otherwise, 
the Registrant has been advised that in the opinion of the Securities and 
Exchange Commission such indemnification is against public policy as expressly 
in the Act and is, therefore, unenforceable. In the event that a claim for 
indemnification against such liabilities (other than the payment by the 
Registrant of expenses incurred or paid by a director, officer or controlling 
person of the Registrant in the successful defense of any action, suit or 
proceeding) is asserted by such director, officer or controlling person in 
connection with the securities being registered, the Registrant will, unless in 
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such 
indemnification by it is against public policy as expressed in the Act and will 
be governed by the final adjudication of such issue.
<PAGE>
 
                                  SIGNATURES

     The Registrant.  Pursuant to the requirements of the Securities Act of 
1933, the Registrant certifies that it has reasonable grounds to believe that it
meets all 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 Valley Forge, Pennsylvania, on the 13th day of December, 
1996.

                                              UNISOURCE WORLDWIDE, INC.



Date:  December 13, 1996                      By: /s/ Jack H. Keeney
                                                 ------------------------------
                                                     (Jack H. Keeney)
                                                     Vice President-Finance
                                                   (Principal Accounting Officer
                                                    and Acting Principal 
                                                    Financial Officer)



     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.

<TABLE> 
<CAPTION> 
        Signature                  Title                         Date
        ---------                  -----                         ----
<S>                          <C>                            <C> 

    /s/ Ray B. Mundt         Chairman and Chief             December 13, 1996
-------------------------    Executive Officer
       (Ray B. Mundt)        (Principal Executive Officer)


    /s/ Charles F. White     President and Chief            December 13, 1996
-------------------------    Operating Officer         
       (Charles F. White)


    /s/ Jack H. Keeney       Vice President-Finance         December 13, 1996
-------------------------    (Principal Accounting
       (Jack H. Keeney)      Officer and Acting
                             Principal Financial Officer)


    /s/ John E. Stuart      Sole Director                   December 13, 1996
-------------------------
       (John E. Stuart)
</TABLE> 



        The Plan.  Pursuant to the requirements of the Securities Act of 1933, 
the trustees (or other persons who administer the employee benefit plan) have 
duly caused this registration statement to be signed on its behalf by the 
undersigned, thereunto duly authorized, in the City of Valley Forge, 
Commonwealth of Pennsylvania, on December 13, 1996.



By:  /s/ ALISTAIR McCREE
   --------------------------------------
Name:  (Alistair McCree)
     ---------------------------------
Title:  Director - Unisource Retirement Plans
      ---------------------------------------
<PAGE>
 
                               INDEX TO EXHIBITS
                               -----------------


Exhibit
Number                      Exhibits
------                      --------

(4.1)           Rights Agreement between the Registrant 
                and National City Bank, the form of which 
                was filed as Exhibit 2.2 to the Registrant's
                Registration Statement on Form 10 (effective 
                November 26, 1996), is incorporated herein 
                by reference.

(5)             Opinion of Morgan, Lewis & Bockius as to 
                the validity of the securities.

(23)            Consent of Independent Auditors.

(99)            Unisource Worldwide, Inc. Partners' Stock 
                Purchase Plan.
[{"type": "S-8", "sequence": "1", "description": "FORM S-8 REGISTRATION STATEMENT", "secsgml_size_bytes": 14667}]
{"company-data": {"conformed-name": "UNISOURCE WORLDWIDE INC", "cik": "0001027282", "assigned-sic": "5110", "state-of-incorporation": "DE", "fiscal-year-end": "0930"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-17947", "film-number": "96681346"}, "business-address": {"street1": "825 DUPORTAIL ROAD", "city": "WAYNE", "state": "PA", "zip": "19087", "phone": "6102968000"}}
As filed with the Securities and Exchange Commission on December 16, 1996

                                                                Registration No.

                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

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

                                   FORM S-8
                            REGISTRATION STATEMENT
                       Under The Securities Act of 1933

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

                           UNISOURCE WORLDWIDE, INC.
              (exact name of registrant as specified in charter)

           DELEWARE                                       13-5369500
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
 incorporation or organization)

                              825 Duportail Road
                        Wayne, Pennsylvania 19087-5589
              (Address of principal executive offices)(Zip Code)

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

                           UNISOURCE WORLDWIDE, INC.
                         PARTNERS' STOCK PURCHASE PLAN
                           (Full title of the Plan)

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

                                Hugh G. Moulton
           Executive Vice President and Chief Administrative Officer
                           Unisource Worldwide, Inc.
                              825 Duportail Road
                        Wayne, Pennsylvania 19087-5589
                    (Name and address of agent for service)

                                (610) 296-8000
         (Telephone number, including area code, of agent for service)

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

                        CALCULATION OF REGISTRATION FEE
Proposed      Proposed
                                 maximum       maximum
  Title of        Amount         offering      aggregate      Amount of
securities to     to be          price         offering      registration
be registered     registered     per unit      price             fee
--------------------------------------------------------------------------------
Common Stock      1,000,000      $19.50(1)     $19,500,000      $5,909
$0.001 
par value

--------------------------------------------------------------------------------
(1)  Calculated in accordance with Rule 457 (c) and (h) based upon the December
     10, 1996 closing quotation for when-issued common stock on the New York
     Stock Exchange.
PART I
                                    ------
 
             INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1.  Plan Information
-------------------------

     A prospectus setting forth the information required by Part I of Form S-8 
will be sent or given to participants as specified by Rule 428(b)(1).

Item 2.  Registrant Information and Employee Plan Annual Information
--------------------------------------------------------------------

     The documents incorporated by reference in Item 3 of Part II of this Form 
S-8 are incorporated by reference in the Section 10(a) prospectus relating to 
this registration statement.  The foregoing documents and all other documents 
required to be delivered to employees pursuant to Rule 428(b) are available 
without charge, upon written or oral request, to Unisource Worldwide, Inc., 825 
Duportail Road, Wayne, PA 19087, Attn:  Corporate Communications Department 
(telephone number: (610) 296-8000).

                                    PART II
                                    -------

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference
------------------------------------------------

     The Registrant's Registration Statement on Form 10 (effective November 26, 
1996) is incorporated by reference by the Registrant and the Plan in this 
registration statement.

     All documents subsequently filed by the Registrant pursuant to Sections 
13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the 
filing of a post-effective amendment indicating that all securities offered
hereby have been sold or which deregisters all securities then remaining unsold,
shall be deemed to be incorporated by reference in this Registration Statement
and to be part thereof from the date of filing of such documents.

Item 4.  Description of Securities
----------------------------------

     Not Applicable.

Item 5.  Interests of Named Experts and Counsel
-----------------------------------------------

     Not applicable.
Item 6. Indemnification of Directors and Officers
-------------------------------------------------

     The Delaware General Corporation Law (the "DGCL"), under which the 
Registrant is organized, provides that the Registrant may indemnify persons who 
incur certain liabilities or expenses by reason of such persons being or having 
been directors, officers or employees of the Registrant or serving or having 
served in such capacities or similar capacities at the Registrant's request for 
other corporations or entities. Pursuant to the DGCL, the Registrant has 
adopted, as part of its By-Laws, provisions whereby the Registrant shall 
indemnify such persons against such liabilities and expenses resulting from 
suits or other proceedings brought by third persons and against expenses 
resulting from suits or other proceedings brought in the right of the 
Registrant. No indemnification against expenses is to be made, however, in 
respect of (i) any breach of the director's duty of loyalty to the Registrant or
its stockholders, (ii) for acts or omissions not in good faith or which involve 
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the DGCL, relating to prohibited dividends, distributions and repurchases or 
redemptions of stock, or (iv) for any transaction for which the director derives
and improper personal benefit.

     As permitted by law, the Registrant has purchased liability insurance 
policies covering its directors and officers to provide protection where the law
does not allow the Registrant to indemnify a director or officer. The policies 
also provide coverage for indemnifiable expenses, including expenses related to 
claims arising under the Employment Retirement Income Security Act against a 
director or officer based upon an alleged breach of fiduciary duty or other 
wrongful act with respect to an employee benefit plan.

Item 7. Exemption from Registration Claimed
-------------------------------------------

     Not applicable.

Item 8. Exhibits
----------------

     (4)   Rights Agreement, between the Registrant and National City Bank, the
           form of which was filed as Exhibit 2.2 to the Registrant's
           Registration Statement on Form 10 (effective November 26, 1996), is
           incorporated herein by reference.

     (5)   Opinion of Morgan, Lewis & Bockius as to the validity of the 
           securities.

     (23)  Consent of Independent Auditors.

     (99)  Unisource Worldwide, Inc. Partners' Stock Purchase Plan.
Item 9. Undertakings
--------------------

        (a)    The Registrant hereby undertakes:

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

                      (i)    To include any prospectus required by Section 
10(a)(3) of the Securities Act of 1933;

                      (ii)   To reflect in the prospectus any facts or events 
arising after the effective date of the registration statement (or the most 
recent post-effective amendment thereof) which, individually or in the 
aggregate, represent a fundamental change in the information set forth in the 
registration statement;

                      (iii)  To include any material information with respect to
the plan of distribution not previously disclosed in the registration statement 
or any material change to such information in the registration statement;

        Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
if the registration statement is on Form S-3 or Form S-8, and the information 
required to be included in a post-effective amendment by those paragraphs is 
contained in periodic reports filed by the Registrant pursuant to Section 13 or 
Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by 
reference in the registration statement.

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

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

        (b)    The Registrant hereby undertakes that, for purposes of 
determining any liability under the Securities Act of 1933, each filing of the 
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the 
Securities Exchange Act of 1934 (and, where applicable, each filing of an 
employee benefit plan's annual report pursuant to Section 15(d) of the 
Securities Exchange Act of 1934) that is incorporated by reference in the 
registration statement shall be deemed to be a new registration statement 
relating to the securities offered therein, and the offering of such securities 
at that time shall be deemed to be the initial bona fide offering thereof.
(c)    Insofar as indemnification for liabilities arising under the 
Securities Act of 1933 may be permitted to directors, officers and controlling 
persons of the Registrant pursuant to the foregoing provisions, or otherwise, 
the Registrant has been advised that in the opinion of the Securities and 
Exchange Commission such indemnification is against public policy as expressly 
in the Act and is, therefore, unenforceable. In the event that a claim for 
indemnification against such liabilities (other than the payment by the 
Registrant of expenses incurred or paid by a director, officer or controlling 
person of the Registrant in the successful defense of any action, suit or 
proceeding) is asserted by such director, officer or controlling person in 
connection with the securities being registered, the Registrant will, unless in 
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such 
indemnification by it is against public policy as expressed in the Act and will 
be governed by the final adjudication of such issue.
SIGNATURES

     The Registrant.  Pursuant to the requirements of the Securities Act of 
1933, the Registrant certifies that it has reasonable grounds to believe that it
meets all 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 Valley Forge, Pennsylvania, on the 13th day of December, 
1996.

                                              UNISOURCE WORLDWIDE, INC.

Date:  December 13, 1996                      By: /s/ Jack H. Keeney
                                                 ------------------------------
                                                     (Jack H. Keeney)
                                                     Vice President-Finance
                                                   (Principal Accounting Officer
                                                    and Acting Principal 
                                                    Financial Officer)

     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/ Ray B. Mundt         Chairman and Chief             December 13, 1996
-------------------------    Executive Officer
       (Ray B. Mundt)        (Principal Executive Officer)

    /s/ Charles F. White     President and Chief            December 13, 1996
-------------------------    Operating Officer         
       (Charles F. White)

    /s/ Jack H. Keeney       Vice President-Finance         December 13, 1996
-------------------------    (Principal Accounting
       (Jack H. Keeney)      Officer and Acting
                             Principal Financial Officer)

    /s/ John E. Stuart      Sole Director                   December 13, 1996
-------------------------
       (John E. Stuart)
The Plan.  Pursuant to the requirements of the Securities Act of 1933, 
the trustees (or other persons who administer the employee benefit plan) have 
duly caused this registration statement to be signed on its behalf by the 
undersigned, thereunto duly authorized, in the City of Valley Forge, 
Commonwealth of Pennsylvania, on December 13, 1996.

By:  /s/ ALISTAIR McCREE
   --------------------------------------
Name:  (Alistair McCree)
     ---------------------------------
Title:  Director - Unisource Retirement Plans
      ---------------------------------------
INDEX TO EXHIBITS
                               -----------------

Exhibit
Number                      Exhibits
------                      --------

(4.1)           Rights Agreement between the Registrant 
                and National City Bank, the form of which 
                was filed as Exhibit 2.2 to the Registrant's
                Registration Statement on Form 10 (effective 
                November 26, 1996), is incorporated herein 
                by reference.

(5)             Opinion of Morgan, Lewis & Bockius as to 
                the validity of the securities.

(23)            Consent of Independent Auditors.

(99)            Unisource Worldwide, Inc. Partners' Stock 
                Purchase Plan.