The authors analysed in a retrospective study the clinical features, ECG and enzyme examinations of 97 patients who died in acute myocardial infarction proved by autopsy during 9 years in their department. They found the recognition rate of the acute myocardial infarction 73%, compared to the data of the literature good. There occurred 26 unrecognized myocardial infarctions, among which atypical clinical features were more frequent and typical ECG signs and enzyme values were less frequent, than among the recognized cases. In their earlier study 57% of the recognized acute myocardial infarctions occurred on the posterior wall, in the present one the rate of anterior and posterior cases was the same. In the earlier study from 95 posterior acute myocardial infarctions 35 (41%) were unrecognized, in present from 41 cases only 11 (27%). This 14% improvement in the recognition rate of the posterior myocardial infarctions should be attributed to the routine application of paravertebral ECG leads, but statistically was not significant.