The Samotrace program aims to describe the prevalence of mental health problems in the workplace and their associated occupational exposures. The sample (6,056 individuals) was selected at random from employees monitored by a network of occupational physicians in the Centre, Pays de la Loire, and Poitou-Charentes regions between 2006 and 2008. The psychosocial work environment was described primarily using Karasek’s work strain model, Siegrist’s effort-reward imbalance model, and exposure to physical and psychological violence. Three indicators of mental health were examined: psychological distress (GHQ-28), alcohol problems, and the use of psychotropic medications. White-collar and blue-collar workers were generally the most exposed to psychosocial occupational factors. There were few differences in the prevalence of mental health disorders by social category, but the prevalence appeared to be higher among women and in the sectors of electricity, gas, and water production and distribution; financial activities; and public administration. Links between certain psychosocial exposures and psychological distress as well as the use of psychotropic medications were described; no link was observed with alcohol-related problems. This study shows that occupational psychosocial risks generally vary depending on the indicator considered, both for mental health problems and for the associated psychosocial exposures. Nevertheless, certain overall trends can be identified and may guide further research.