Lack of documented comparative information has led to increasing confusion regarding relative merits of the various corticosteroid preparations in treatment of rheumatoid arthritis. Tested in a group of 65 patients with active rheumatoid arthritis were prednisone, prednisolone, methylprednisolone, triamcinolone, and dexamethasone. Comparable antirheumatic benefit was obtained with all compounds in the majority of patients. No one preparation demonstrated any consistently superior therapeutic advantage. Factors influencing choice of treatment include probable effectiveness, nature of unwanted side-effects, ease of administration, and cost to the patient.