A study of 690 osteoarthrosis (OA) patients with corresponding controls, and 475 soft-tissue rheumatism (STR) patients with the same number of controls was made in Finnish health centres. The aim of the study was to clarify certain etiological, social and therapeutical aspects. No clear differences were found in the working conditions of patients with OA, STR, or their controls, or in their occupational classes. OA patients were less satisfied with their working conditions than were the other. OA and STR patients had been more actively engaged in sports earlier in life, but during the study there were no differences; nor did the localisation of OA differ. The weight index qas slightly higher in OA, particularly when knee and ankle were affected, but not with arthrosis of the hip. There were no clear associations with other diseases. The maximum duration of a treatment period in this study was 1 month. The average sick leave in OA was 17.8 days, in STR 13.4 and in controls 15.4 days. After treatment, 31% of OA patients, and 56% of STR were recommended to resume work; 4% were recommended to change their occupation; 21% of OA and 7% of STR patients were recommended to retire on pension. Sulindac, indomethacin and many other drug combinations were used for medication. Certain side effects were found in about 5% of sulindac- and in 8-10% of indomethacin-treated patients. In 17% of OA and in 12% of STR patients, it was found necessary to consult a specialist for diagnosis or treatment.