One hundred and seventeen outpatients (87 females and 30 males; mean age 53.5 +/- 13.2 years) encompassing the 1987 American Rheumatism Association criteria for rheumatoid arthritis were admitted into a multicentre open study. All patients were evaluated at baseline and after two months of therapy with etodolac (400 or 600 mg/die per os). Clinical evaluation was performed by using the following indicators: viso-analogic scale of global pain; index of pain on active movements; index for sleep disturbances, and duration of morning stiffness. The erythrocyte sedimentation rate was chosen for the laboratory evaluation of the activity of the disease. One hundred patients received 400 mg/die, while only 17 patients received 600 mg/die; 115 patients undertook the evaluation after treatment, whereas two patients were considered "lost to follow-up". One hundred and five patients completed the study while ten patients withdrew (seven because of inefficacy and three because of intolerance of the gastrointestinal tract). Only nine patients presented side-effects, among these: five were judged etodolac-related, whereas four were not. A complete resolution of all these side-effects was achieved in all cases. Significant improvements were registered for all the four clinical variables. At the end of the study 56.5% of patients expressed a preference for etodolac, 16.5% for one of the non-steroidal anti-inflammatory drugs previously taken and 27% did not answer or were not able to express any definite preference. Strict concordance was found between the degree of clinical improvement achieved and the preferences expressed. The laboratory parameters did not reveal any variation at the end of the study in comparison with baseline values.(ABSTRACT TRUNCATED AT 250 WORDS)