Myocardial infarction is encountered in diabetic patients more frequently and is usually associated with a higher mortality rate, as compared with the normal population. The authors investigated the relationship between myocardial infarction and diabetes in a group of 408 patients with myocardial infarction, incl. 144 (32%) type 2 diabetics most of them treated by diet or PAD. In the group of diabetics with myocardial infarction a higher incidence of hypertension was recorded and more frequent use of nitrates. The incidence of obesity, smoking angina pectoris, a previous infarction with a pain-free course and family-history were comparable in the two groups. Diabetic patients suffered significantly more frequently from non-Q infarction of the heart muscle (p < 0.5) and infarctions of the anterior wall (p < 0.001). The mortality during hospitalization was 24% in the group of diabetics, while it was 17% in non-diabetic patients.