The authors report fifty-nine cases of non-transmural myocardial infarction. The diagnosis was made on the basis of clinical electrocardiographic data and enzyme changes. The clinical course was characterized by several chest pain attacks; a transmural myocardial infarction occurred in four patients a few days after admission. Out of fifty-five patients, followed for a nineteen - months period, six died, thirty-one were asymptomatic and fourteen complained of angina. In the last group, chest pain was generally present before the non-transumural myocardial infarction. The ECG were within normal limits in thirty-seven patients. The coronarographic patterns found in fifteen patients are also described and discussed.