The pilot epidemiological surveillance network for musculoskeletal disorders (MSDs) in the Pays de la Loire region, established by the French Institute for Public Health Surveillance in 2002, provides unprecedented data on the prevalence of MSDs and their risk factors among the working population. In 2002 and 2003, a sentinel network of 80 volunteer occupational physicians enabled the random selection of 2,685 employees representative of the region’s workforce. The six main upper extremity MSDs are clinically diagnosed by occupational physicians according to a rigorous clinical protocol (European SALTSA consensus). Occupational exposure is assessed using a self-administered questionnaire focusing on biomechanical and psychosocial risk factors for MSDs. The high prevalence of MSDs, combined with significant biomechanical and psychosocial stressors, underscores the need for a comprehensive approach to MSD prevention in the workplace to reduce risk exposure and ensure that employees suffering from MSDs can remain in or return to work. (R.A.)