Some of the "risk" factors implicated in the etiology of coronary atherosclerotic heart disease were investigated in sixty Quechua men living in two areas of Peru. Highland Quechua had higher serum triglycerides (mean, 122 vs. 90 mg. per deciliter) than downward migrants. There were no significant differences between the two groups in serum cholesterol (mean 150 vs. 157 mg. per deciliter), body fat (mean, 15 vs. 17%), or blood pressure (mean, 113/72 vs. 114/72 mm Hg). Both groups consumed about 2,500 kcal per man per day, while the highland Quechua consumed more carbohydrate (mean, 66 vs. 51%) and less fat (mean 19 vs. 33%). By American standards, both groups had low serum cholesterol values, as well as low blood pressure.