This study found that overall, professional football players had a 46 percent lower overall mortality rate than the general United States male population with a similar age and race distribution. However, those who played on the offensive and defensive line had a 50 percent greater risk of cardiovascular disease than the general population. When compared to other football players, the linemen had a 3.7 times greater risk of cardiovascular disease. Those in the largest Body Mass Index (BMI) category (32 or greater) had a 6 times greater risk than those players who were in the lowest BMI category. An association with position and BMI was found both for ischemic and non-ischemic causes of cardiovascular deaths. It is not possible from this analysis to determine specifically what it is about the linemen, besides BMI, that contributes to this increased risk. Although other research studies have found an association between cardiovascular disease and BMI (obesity), elevated BMI generally has not been as strong a risk factor as found in this study. This suggests to us that other factors, which we were not able to measure, could be contributing to the increased risk of cardiovascular disease among linemen. Some of the specific risk factors for cardiovascular disease which are associated with obesity include high blood pressure, decreased HDL cholesterol, and decreased glucose tolerance (diabetes). It has been suggested that anabolic steroid use might be a risk factor for cardiovascular disease, but no information was available to us regarding their use by specific individuals or groups of players. We did not have information on many of the established risk factors for cardiovascular disease including smoking history, blood pressure, and cholesterol levels. The respiratory disease rates, however, do not suggest that smoking in this population is any more prevalent than in the comparison U. S. population. Additionally, our information on BMI was limited to reported heights and weights during the last season played since we did not have information on changes in weight after the men left professional football. Despite these limitations, this study shows that certain groups of football players are at an elevated risk for cardiovascular disease, and should be encouraged to have regular medical check-ups. Appropriate control of cholesterol, blood pressure, and weight have been shown to effectively prevent cardiovascular deaths. This study provides additional evidence for the importance of obesity as a risk factor for heath disease, even among a group of professional athletes. Finally we would suggest that there be continued surveillance of this population. Further follow-up of mortality in approximately five years would be useful in resolving some issues, such as whether the observed increase in Hodgkin's disease and ALS occurred by chance.