QuickLinks -- Click here to rapidly navigate through this document

FORM 6-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16
of the Securities Exchange Act of 1934

Date: December 6, 2004
Commission File Number 001-31528

IAMGold Corporation
(Translation of registrant's name into English)

220 Bay Street, 5th Floor
Toronto, Ontario M5J 2W4, Canada
Tel: (416) 360-4710

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F o                        Form 40-F ý

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):                             

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):                             

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes o                        No ý

If "Yes" is marked, indicate below the file number assigned to the registrant in connection with
Rule 12g3-2(b): 82-                             





Signatures

        Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

    IAMGOLD CORPORATION

Date: December 6, 2004

 

By:

 

/s/  
LARRY E. PHILLIPS      
Larry E. Phillips
Vice-President, Corporate Affairs &
Corporate Secretary


EXHIBIT INDEX

Exhibit

  Description
99.1   Supplemental Information, dated December 6, 2004, of IAMGold Corporation.
99.2   Material Change Report, dated December 6, 2004, of IAMGold Corporation.



QuickLinks

Signatures
EXHIBIT INDEX