Fish lipids contain large amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid. These fatty acids are known to have an influence on prostaglandin (PG) and leukotriene (LT) synthesis. We studied the effect of a fish oil dietary supplement on an immune-complex-induced keratitis of the rabbit eye and compared it with the effect of a sunflower seed oil dietary supplement, rich in linoleic acid. Immune complex keratitis induced by intrastromal injection of human serum albumin (HSA) was characterized by leukocyte infiltrate, neovascularization, and corneal edema. Animals given a fish oil diet showed significantly less leukocyte infiltrate, neovascularization, and corneal edema, compared to those given a sunflower seed oil diet.