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

                                    Form 13F

                              Form 13F COVER PAGE

Report for the Calendar Year or Quarter Ended: September 30, 2006

Check here if Amendment [ X]; Amendment Number: 1
This Amendment (Check only one.): [  ] is a restatement.
                                  [ X] adds new holdings entries.

Institutional Investment Manager Filing this Report:

Name:    Robeco USA, LLC
Address: 909 Third Avenue
         New York, NY  10022

13F File Number:  28-00014

The institutional investment manager filing this report and the person by whom
it is signed hereby represent that the person signing the report is authorized
to submit it, that all information contained herein is true, correct and
complete, and that it is understood that all required items, statements,
schedules, lists, and tables, are considered integral parts of this form.

Person Signing this Report on Behalf of Reporting Manager:

Name:      Mary Ann Iudice
Title:     Chief Compliance Officer
Phone:     212-908-9620

Signature, Place, and Date of Signing:

     /s/ Mary Ann Iudice     New York, NY     January 08, 2007


Report Type (Check only one.):

[ X]         13F HOLDINGS REPORT.

[  ]         13F NOTICE.

[  ]         13F COMBINATION REPORT.


List of Other Managers Reporting for this Manager

Robeco Investment Management, Inc., as successor via merger to Robeco USA, LLC



                              FORM 13F SUMMARY PAGE


Report Summary:

Number of Other Included Managers:         0

Form13F Information Table Entry Total:     1

Form13F Information Table Value Total:     $7,023 (thousands)


List of Other Included Managers:

Provide a numbered list of the name(s) and Form 13F file number(s) of all
institutional managers with respect to which this report is filed, other
than the manager filing this report.

NONE






             
                                                     FORM 13F INFORMATION TABLE
                                                             VALUE  SHARES/ SH/ PUT/ INVSTMT  OTHER            VOTING AUTHORITY
NAME OF ISSUER                 TITLE OF CLASS   CUSIP     (x$1000)  PRN AMT PRN CALL DSCRETN MANAGERS         SOLE   SHARED     NONE
------------------------------ ---------------- --------- -------- -------- --- ---- ------- ------------ -------- -------- --------
MDC PARTNERS INC               CL A SUB VTG     552697104     7023   970045 SH       SOLE                   970045        0        0