The authors have determined the timing and details of the recourse to surgery in a cohort of 288 non-selected cases of rheumatoid arthritis. This was necessary in one third of the patients after a mean follow-up period of 10 years. The same was true for patients followed up as out-patients as for those hospitalized during the active progress of the disease. Fifteen percent of the patient in the cohort received total replacement of a large joint by a prosthesis. Orthopedic surgery makes a major contribution towards improving the functional prognosis in rheumatoid arthritis.