This system relies on a sentinel network of volunteer occupational physicians who, twice a year for two consecutive weeks, report all cases of work-related illnesses (WRI) observed among all employees seen during that period. The characteristics (age, gender, occupation, industry) of all employees who underwent a medical examination during the period were also collected to calculate the prevalence of these OWDs. Participating occupational physicians provide their annual assigned caseloads to assess their representativeness. This survey is strictly anonymous with regard to employees presenting with an OHD. This brochure presents the results of the first year of the study in Poitou-Charentes, which covered two two-week periods: June 12–23, 2006, and November 20–December 1, 2006.