Objective. To determine whether a combination of borage seed oil rich in gamma linolenic acid (GLA) and fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is superior to either oil alone for treatment of rheumatoid arthritis (RA). Methods. Patients were randomized into a double-blind, 18-month trial. Mixed effects models compared trends over time in disease activity measures. Results. No significant differences were observed in changes in disease activity among the three randomized groups. Each group exhibited significant reductions in disease activity (DAS28) at 9 months (fish: -1.56[-2.16, -0.96], borage: -1.33[-1.83, -0.84], combined: -1.18[-1.83, -0.54]) and in CDAI (fish: -16.95[-19.91, -13.98], borage: -11.20[-14.21, -8.19], and combined: -10.31[-13.61, -7.01]). There were no significant differences in change of RA medications among the three groups. Reduced disease activity in study patients was similar to matched patients from an RA registry, and reduction in DMARD use was greater (P < 0.03) in study patients. Conclusion. All 3 treatment groups exhibited similar meaningful clinical responses after 9 months, improvements which persisted for 18 months, and a response similar to matched patients from an RA registry. Study patients were able to reduce DMARD therapy given in combination with TNF antagonists to a greater extent than registry patients. This paper is dedicated to the memory of Dr. John T. Sharp, M.D., a pioneer and innovator in the field of musculoskeletal radiology.