The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F COVER PAGE

OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8

Report for the Calendar Year or Quarter Ended: 03-31-2023
Check here if Amendment    Amendment Number:
This Amendment (Check only one.):    is a restatement.
   adds new holdings entries.
Institutional Investment Manager Filing this Report:
Name: Robeco Institutional Asset Management B.V.
Address: WEENA 850
ROTTERDAM, P7  3014DA
Form 13F File Number: 028-12635
CRD Number (if applicable):
SEC File Number (if applicable):

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: Joost van der Linden
Title: Head of Compliance
Phone: 0031651522094
Signature, Place, and Date of Signing:
/s/ Joost van der Linden RotterdamP7 05-03-2023
[Signature] [City, State] [Date]
Report Type (Check only one.):
   13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager are reported in this report.)
   13F NOTICE. (Check here if no holdings reported are in this report, and all holdings are reported by other reporting manager(s).)
X 13F COMBINATION REPORT. (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s).)
List of Other Managers Reporting for this Manager:
[If there are no entries in this list, omit this section.]
Name Form 13F File No. CRD No. (if applicable) SEC File No. (if applicable) CIK
Boston Partners 028-12484     0001386060
Robeco Schweiz AG 028-12627     0001418427
HARBOR CAPITAL ADVISORS, INC. 028-21112     0001039128
Form 13F Summary Page
Report Summary:
Number of Other Included Managers: 2
Form 13F Information Table Entry Total: 1,044
Form 13F Information Table Value Total: 36,682,902,683
(round to nearest dollar)
List of Other Included Managers:
Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report.
[If there are no entries in this list, state “NONE” and omit the column headings and list entries.]
No. Name Form 13F File No. CRD No. (if applicable) SEC File No. (if applicable) CIK
1 ORIX CORP 028-18337     0001070304
2 ORIX Corp Europe N.V. 028-12637     0001257165