Limited data are available on current levels and time related changes in risk factors for ischemic cardiovascular disease among American Indians. Because of the absence of systematic surveys of defined populations and the lack of standardization of methodology employed in studies of different groups, it is difficult to interpret apparent increases in risk factors over time or to explain apparent differences in cardiovascular disease rates by differences in risk factor distributions. Studies of current risk factor levels and distributions are of great importance, however, since they may provide the best estimates of the future relative risk of cardiovascular disease within the Indian population.