Purpose of the study: We studied the evolution of medial epicondylitis, the association with other work related musculoskeletal disorders, and the consequences for prevention. Methods: In 1993-1994 and again in 1996-1997, 598 workers exposed to repetitive job were examined by 18 occupational health physicians and completed a self-administered questionnaire. The study was performed in order to consider all upper-limb occupational disorders; we focused here on the evolution and prevention of medial epicondylitis. Results: Prevalence was 5.2 percent in this population. Annual incidence was estimated at 1.5 percent. Medial epicondylitis had a good medical (recovering rate 81 % CI [63%;92%]) and professional prognosis. There was a claim for occupational disease compensation for four percent of medial epicondylitis. Forceful job was associated with prevalence, but was not found as a risk factor for incidence. Other upper-limb occupational disorders, especially shoulder tendinitis, carpal tunnel syndrome, lateral epicondylitis, and ulnar nerve syndrome at elbow were associated with incidence of medial epicondylitis (Relative Risk = 2.5 ;CI[1.01;6.00]), suggesting that this disorder is secondary to other work-related disorders. Conclusions: Medial epicondylitis had a good prognosis in our study. The disorder could be detected easily by the occupational physicians, especially in the population at high risk. In our study, workers recovered without changing their working conditions