Cyclophosphamide, azathioprine, and hydroxychloroquine sulfate were prescribed for 31 patients (26 women and five men) with rheumatoid arthritis refractory to conventional therapy. Maintenance drug dosages (mean +/- SD) were as follows: cyclophosphamide, 30 +/- 24 mg/day; azathioprine, 74 +/- 44 mg/day; and hydroxychloroquine sulfate, 210 +/- 92 mg/day. Disease suppression began in 30 patients within three to 24 months (mean, nine months). Results after 43 months (range, 12 to 102 months) were as follows: 16, complete remission; seven, near remission; seven, partial disease suppression; one, no response. None remained in prolonged remission without some form of therapy. Treatment was discontinued in three patients because of pulmonary infection (two) or thrombocytopenia (one). Four patients had five malignant neoplasms (surgical cures) before therapy (two breast, one colon, one melanoma, one endometrial); four patients developed a malignant neoplasm during combined drug therapy (one colon, one endometrial, one lung, one erythroleukemia); and three died. The absolute risk of malignancy from combined drug therapy is still unclear. We concluded that combined use of remittive agents may have promise in treatment of severe rheumatoid arthritis; cyclophosphamide should be replaced with a nonalkylating agent; and the place of combined drug therapy remains uncertain in the absence of controlled trials.