Cardiovascular mortality in the State of Utah is among the lowest in the United States. The religion of 72% of the state residents (Mormon) proscribes the use of tobacco and alcohol; a large number of Mormons adhere to this proscription. This study analyzed the 6108 cardiovascular disease deaths between 1969--1971 in Utah of members in the Mormon Church. For both sexes, Mormons had 35% less mortality than expected from US rates for ischemic heart disease, while non-Mormons were not significantly different from US whites. These results support the relationship between cigarette smoking and mortality from cardiovascular disease. Mormon men also had lower mortality from hypertensive heart disease and Mormon women from rheumatic heart disease than non-Mormons in Utah.