A total of 453 rheumatoid arthritis (RA) patients were followed up for 35.2 +/- 27.9 months (range 3-106). The clinical parameters decreased significantly after 6 months. Twenty-eight patients were in remission (6.4%). Rheumatoid factor (RF) positivity was less common in the group of patients in remission, with a higher frequency of visits and methotrexate (MTX) onset after 65 yr. There was a significant degradation of radiographic lesions (n = 60). A total of 101 patients (23.1%) stopped MTX, for toxicity (n = 61) and failure (n = 20). The onset of MTX after 65 yr, a low number of visits and the occurrence of side-effects were predictive of MTX withdrawal. A total of 259 patients (59.3%) had side-effects. A Ritchie's index < or = 10, a lower polymorphonuclear cell count and the absence of RF were predictive of side-effects. The probability of being on MTX at 5 yr was 73%. This study confirms the high efficacy of MTX in RA.