The population of northern Sweden shows a marked ethnic heterogeneity and a unique distribution of disorders with a monogenic or polygenic background, among them cardiovascular diseases. We have studied variations between 23 North Swedish subpopulations (regions) with respect to hypercholesterolemia and its possible determinants including dietary factors, obesity and the degree of Finnish genetic influence. A significant regional heterogeneity was found concerning hypercholesterolemia, obesity and high consumption of ‘boiled’ coffee. Hypercholesterolemia showed significant geographical covariations with Finnish genetic influence and consumption of ‘boiled’ coffee. The results are consistent with the hypothesis that in addition to environmental factors Finnish genetic influence contributes to the development of hypercholesterolemia and thereby to the increased rate of cardiovascular disease found in northern