After baseline aspirin therapy, 89 rheumatoid arthritis patients completed a double-blind, crossover trial comparing ibuprofen, fenoprofen, naproxen, and tolmetin. Initially, patients took the manufacturer's recommended starting dose; this could be increased by 50% within the first 2 weeks of therapy. Patients remained at the chosen dose for 4 weeks and then changed to the next drug. All 4 drugs were tolerated better than aspirin (p less than 0.001). There were no statistically significant differences among the 4 drugs for any efficacy measurements. However, patients' and physicians' rankings showed the same order of preferences: naproxen, ibuprofen, fenoprofen, tolmetin, and aspirin.