The surveillance programme of work-related diseases (WRD) is based on a network of occupational physicians who notify all WRD diagnosed during a two-week observation period. The aims are mainly to estimate the prevalence of non-compensated WRD in the working population according to socio economic factors; to determine new indicators of occupational health; to update the lists of compensable occupational diseases; to understand and assess under-compensation and under-notification. The participation rate for occupational physicians is around 33% in 2008. The main WRD are the musculoskeletal disorders, followed by the mental disorders. This 2-week protocol, repeated regularly, provides useful data on frequency of pathologies linked to employment as well as an estimate of unreported WRD subject to compensation or non-compensated WRDs, and the trends of WRDs over the time.