In the last decade the possible role of dietary therapy in the treatment of different rheumatic diseases has undergone serious reconsideration. Elimination diets may be useful in a subgroup of patients with rheumatoid arthritis, in whom food antigens probably play an important role in the onset and perpetuation of the inflammatory process. In mixed cryoglobulinemia a low-antigen-diet might reduce the amount of macromolecular food antigens which cross the mucosal barrier of the gut and cause either an immune response and/or compete with the immune complexes in the mononuclear phagocytic system. Supplementing the diet with essential fatty acids (omega-3 and/or omega-6) may inhibit the production of some of the mediators of inflammation, such as leukotriene-B4 and interleukin-1. However, currently employed doses often result in only modest or moderate clinical improvement. Controlled studies in a larger number of patients and with differentiated treatment protocols are needed to establish to what extent dietary therapy may improve the course of different rheumatic diseases, and to determine whether this therapy might be used in association with or even substitute for other well recognized treatments.