Zinc, lead, and cadmium were measured in the myocardium (left and right ventricles) and aorta of 14 women and 12 men who had died from acute myocardial infarction (MI), and of 12 control women and 15 control men who had died of acute trauma. Mineral content of the necrotic areas of the MI patients was also determined. There was little significant correlation with age, and sex could not be shown to influence the cation concentrations. Significantly larger concentrations of lead and cadmium were observed in the right ventricle of women controls. In the four populations, significantly higher zinc concentrations were found in the left ventricle. Lead and cadmium levels in aortas were consistently higher than those in left ventricles, whereas zinc levels were always lower. The lead content in the ventricles and aorta of MI victims was consistently greater than for control subjects, though the difference was not significant. However, in the necrotic area, a significant decrease in zinc concentration was noted. These results are discussed and compared with other results published previously. It is concluded that studies in this area must be continued as there are still many uncertainties.