The purpose of the present research was to develop an original self-report questionnaire to assess the structure of the reasons underlying the retirement decision process among French entrepreneurs using the push pull anti-push anti-pull view. Three studies were conducted to examine the reliability and validity of the Reasons for Entrepreneurs’ Retirement Decision Inventory (RERDI). The first study involved creating a list of items leading to a preliminary version of the RERDI. In the second study, 167 French entrepreneurs were surveyed to test the factor structure of the RERDI and to select the final items leading to a 16-item inventory. This tool comprises four reliable subscales: (a) push, (b) pull, (c) anti-push, and (d) anti-pull, with adequate internal consistency. Using confirmatory factor analysis, this four-factor structure was confirmed in the third study (n = 255). The RERDI’s convergent validity and temporal stability were also confirmed. The importance of this inventory for further research and practice is discussed.