Acute myocardial infarction without obstructive atherosclerosis is a well known entity characterized by the young age of the patients, the low incidence of risk factors and the absence of pre- and post infarction angina. The myocardial necrosis is probably caused by a thrombotic phenomenon perhaps initiated and/or exacerbated by a coronary spasm. It is generally thought that recurrence is rare and long term prognosis relatively benign but this may be a misconception. Three cases are reported of patients who had a second myocardial infarction, transmural infarction in each case, 17 to 36 months after the initial event. Prophylactic treatment after the second accident seems undoubtedly indicated. Until large randomized trials have established the best treatment, it appears logical to prescribe antithrombotic drugs (antiplatelet or anticoagulant drugs) with, perhaps, coronary spasmolytic drugs like calcium antagonists.