The objectives of the occupational disease surveillance program (MCP) are to estimate the prevalence rates of occupational diseases, describe the occupational exposure agents associated with these conditions, and contribute to the assessment of underreporting of occupational diseases. For the 2016–2018 period, 34 physicians from the Pays de la Loire region participated (19 in Loire-Atlantique), representing nearly 10% of the region’s occupational physicians. A total of 4,183 employees were seen during this period.