Four males aged 17-42 years with ST-T segment changes suggesting perimyocarditis or non-Q acute myocardial infarction are presented. Coronary angiography was performed to establish the final diagnosis. Three patients had normal coronary arteries; two of them had typical clinical signs of perimyocarditis whereas the third patient had less typical changes. The fourth patient was a smoker, had a family history of coronary heart disease and left ventricular dysfunction due to a non-Q wave apical infarction. In this patient coronary angiography revealed small atheromatous plaques in the distal part of left anterior descending artery as well as left main and right coronary artery spasm. Angiospastic aetiology of infarction and probable endothelial dysfunction due to myocarditis were diagnosed. The authors conclude that coronary angiography is not always helpful if clinical, electrocardiographic and biochemical signs of perimyocarditis are observed.