Essential polyunsaturated fatty acids (PUFA) of the omega-3 family are believed to protect against cardiovascular disease. A rich source of omega-3 PUFA is found in fish and marine mammals (seal, walrus, whale), which are a large part of the traditional diet of Alaska Natives (Eskimo, American Indians, Aleuts), a group that has been reported to have a lower mortality rate from cardiovascular disease than non-Natives. An autopsy study using standardized methods to evaluate the extent of atherosclerosis and its risk factors, and analyses of stored triglyceride fatty acids was conducted in a sample of Alaska Native subjects and non-Native subjects living in Alaska. Findings indicate that Alaska Natives had less advanced atherosclerosis in coronary arteries, along with higher proportions of omega-3 and lower proportions of omega-6 PUFA in adipose tissue, than did non-Natives. We conclude that high dietary intake of omega-3 PUFA may account for the lower extent of coronary artery atherosclerosis, contributing to the reported lower heart disease mortality among Alaska Natives.