Analysis of 62,000 deaths in Iowa men aged 20 to 64 years from 1964 to 1978 indicates that Iowa farm men younger than 65 years have lower than expected mortality for all causes and for ischemic heart disease. Using data gathered by the Iowa Lipid Research Clinics (LRC) Program Prevalence Study, we compared levels of known cardiovascular risk factors in farmers with those of nonfarmers residing in the same rural county. Farm men smoked less frequently (19% v 44%) and engaged in exercise more frequently (83% v 40%) than nonfarmers. Treadmill performance in farm men indicates a higher level of fitness in farmers. Farm people consumed more total calories and cholesterol, but drank less alcohol than nonfarmers. Farm men had significantly higher serum cholesterol levels. High-density lipoprotein cholesterol levels were also higher in farmers. However, when adjusted for age and exercise status, farmers and nonfarmers had similar lipid levels. The results of the LRC survey suggest that the lower mortality rates of Iowa farmers are a reflection of a life-style that includes vigorous exercise and little consumption of alcohol and tobacco.