Since 2003, Santé publique France has been leading the surveillance program for occupational diseases (MCP) in collaboration with the Occupational Health Inspectorate and the regional health observatories of the participating regions. Occupational diseases are generally defined as the result of exposure, of varying duration, to a risk present in the normal course of one’s work. Under certain conditions, the French legal framework allows for the recognition of these diseases by the Social Security systems. However, due in particular to significant underreporting, the recognition data produced regularly do not reflect the reality of occupational risks. Additionally, MCPs are defined as any pathologies or symptoms that may be of occupational origin and that were not recognized as such at the time of the medical examination. Monitoring these MCPs is therefore necessary to better document the health impact of occupational risks. The primary objective of this system is to describe MCPs (prevalence, socioprofessional determinants, associated occupational exposure agents) and their evolution over time, in particular to better target workplace prevention efforts, assess the underreporting of occupational diseases, and provide data for updating occupational disease tables. The MCP surveillance program relies on the voluntary participation of occupational health teams, which, during two-week data collection periods twice a year, report MCP cases, associated occupational exposure agents, and the socioprofessional characteristics of employees seen during medical examinations. For nearly 20 years, the occupational disease surveillance program has adapted to successive reforms of the legislative framework governing occupational medicine and, more specifically, occupational health and safety services (SPST). The purpose of this report is to provide a comprehensive description of how the MCP surveillance system operates, as well as the methodological aspects associated with its implementation. It also aims to present the challenges the program faces, particularly regarding the participation of SPST teams and its rollout across the entire country, as well as the future prospects under consideration.