Introduction - The Samotrace program aims to estimate the prevalence of mental health disorders by occupation and associated occupational exposures. Methods - The program consists of three independent components. Each component is implemented in two pilot geographic areas: the Centre region (and neighboring areas) and the Rhône-Alpes region. The workplace epidemiological surveillance component provides mental health indicators by occupation and industry sector, as well as estimates of exposure to risk factors provided by volunteer occupational physicians. The case study component involves a detailed qualitative analysis of situations involving mental distress or psychopathological decompensation at work. It is conducted by occupational physicians trained in this field. The medical-administrative component identifies all cases of employees placed on disability leave due to mental health issues and relies on the collaboration of medical advisors from the Health Insurance system. Results - Data collection began in the Centre region in January 2006 and will begin in the Rhône-Alpes region in early 2007. Conclusion - The data from this pilot phase will provide an initial overview of mental health disorders by occupation. Ultimately, the goal is to expand the study nationwide and ensure its long-term sustainability. (R.A.)