Several studies have now demonstrated reproducible clinical benefits of rheumatoid arthritis disease activity after ingestion of n-3 fatty acids. Biologic changes induced by fish oils include decreases in the production of leukotriene B4, platelet activating factor and interleukin-1. Investigations now focus on the proper dose and duration of fish-oil dietary intervention in order to obtain optimum clinical effects. Their ultimate therapeutic role has not yet been determined.