Coronary arteries, aortas, blood, adipose tissue, and liver were collected at autopsy from deceased Alaskan natives, aged 5 years and above, dying of all causes and from a similar number of age- and sex-matched non-native Alaskans. Tested standardized methods of gross evaluation, histomorphometry, and chemistry were used to characterize, measure, and evaluate the prevalence and extent of atherosclerosis in arteries. Chemical methods for determination of blood and tissue lipids and gas liquid chromatographic methods for determination of fatty acids in various lipid fractions in plasma and tissues were used. Risk factors for coronary artery disease were evaluated from tissues taken at autopsy. Hypertension was evaluated by an examination of kidney arterioles. Cigarette smoking was evaluated by measurement of thiocyanate in the blood and the presence or absence of diabetes was evaluated by measuring glycosylation of hemoglobin from red blood cells. Findings were compared with those studied in other populations such as Blacks and whites in New Orleans, and Japanese, Norwegians and nineteen other ethnic groups in the International Atherosclerosis Project.