EXHIBIT 5.1

                                                    Osler, Hoskin & Harcourt LLP
                                                         Barristers & Solicitors
                                                  Box 50. 1 First Canadian Place
                                                        Toronto, Ontario M5x 1B8


                                                September 29, 2003


Moore Wallace Incorporated
1200 Lakeside Drive
Bannockburn, IL 60015

Dear Sirs & Mesdames:

MOORE WALLACE INCORPORATED
REGISTRATION STATEMENT ON FORM S-8

We have acted as Ontario counsel to Moore Wallace Incorporated, a corporation
continued under the federal laws of Canada (the "Registrant"), in connection
with options (the "Options") to purchase common shares of the Registrant granted
to a certain employee of the Registrant and evidenced by a certain option
agreement dated April 7, 2003, (the "Option Agreement") entered into between the
Registrant and such employee. We understand that the Registrant has filed a
Registration Statement on Form S-8 (the "Registration Statement") with the
Securities and Exchange Commission under the Securities Act of 1933, as amended,
relating to the offering of a total of 250,000 common shares of the Registrant
(the "Shares") issuable upon the exercise of the Options.

For purposes of expressing the opinion set forth herein, we have examined
originals or copies, satisfactory to us, of all such corporate records and of
all such agreements, certificates and other documents as we have deemed relevant
and necessary as a basis for the opinion hereinafter expressed. In such
examination, we have assumed the genuineness of all signatures, the authenticity
of all documents submitted to us as originals and the conformity with the
original documents of all documents submitted to us as copies. As to any facts
material to such opinion, we have, to the extent that relevant facts were not
independently established by us, relied on certificates of public officials and
certificates of officers or other representatives of the Registrant.

We are solicitors qualified to practice law in the Province of Ontario and
express no opinion as to any laws or any matters governed by any laws other than
the laws of the Province of Ontario and the federal laws of Canada applicable
therein.

Based upon and subject to the foregoing, we are of the opinion that, upon the
exercise of the Options which are duly exercised and paid for in accordance with
the terms of the resolution pursuant to which such Options have been granted and
the Option Agreement, the Shares so issued will be outstanding as fully paid and
non-assessable.

We hereby consent to the use of our opinion as herein set forth as an exhibit to
the Registration Statement. In giving such consent, we do not thereby concede
that we are in the category of persons whose consent is required under Section 7
of the Securities Act of 1933 or the rules and regulations promulgated
thereunder, or that we are "experts" within the meaning of the Securities Act of
1933 or the rules and regulations promulgated thereunder.

Yours very truly,

/s/ Osler, Hoskin & Harcourt LLP