Male Fisher rats were fed chow diets for two weeks after which they were divided into seven groups of ten rats each and fed 20% Canola, 20% menhaden, 20% partially hydrogenated soy oil (PHSO) or chow only, with or without 500 mg/Kg dietary vitamin E in chow containing 2% cholesterol for six weeks. Triglycerides were lower in the menhaden group and were essentially the same in the E supplemented groups as in their unsupplemented cohorts. Plasma cholesterol was higher in the Canola, and lower in the menhaden, groups, compared to the PHSO group. Cholesterol was the same in the E supplemented groups as in their unsupplemented cohorts. Plasma thiobarbituric acid reactant substances (TBARS) were higher in the menhaden group, compared to the chow group. Vitamin E supplementation lowered TBARS in the menhaden and PHSO groups, compared to the unsupplemented cohorts. Collagen induced platelet aggregation was lower in both Canola and menhaden groups, compared to the PHSO group. Vitamin E supplementation lowered collagen induced platelet aggregation only in the PHSO group. Thrombin induced platelet aggregation was lower in the Canola group, compared to the PHSO group. Vitamin E supplementation did not affect thrombin induced platelet aggregation compared to unsupplemented cohorts. Plasma vitamin E levels were lowest in the menhaden supplemented group compared to all other groups not receiving E, suggesting a greater requirement for E in this group. Finally, vitamin E supplementation raised the plasma E levels in all groups except the menhaden group when compared to unsupplemented cohorts.