The objective was to determine the clinical course and predictors of clinical response in patients with rheumatoid arthritis (RA) who are hospitalized for active disease and functional deterioration. Sixty-three patients who were admitted to a rheumatology clinic for multidisciplinary treatment were prospectively evaluated at 2-weekly intervals. During the admission period, which lasted for a mean of 47 +/- 24 days, patients improved significantly according to variables of disease activity, functional status and emotional status. The change in the variables appeared to be linear with time. Twenty-seven patients (43%) fulfilled the Paulus 20% criteria for clinical response during treatment. A long disease duration, a high Larsen erosion score, a high level of disease activity at admission and the institution of a disease-modifying anti-rheumatic drug within 3 months before admission were associated with a clinical response. In patients hospitalized for active disease, improvement appeared to be linear with time during admission. Patients with long-standing, destructive disease and a high level of disease activity improved most during hospitalization.