The authors report the case of a 54 year old surgeon who received an electric shock from his diathermy equipment. The shock caused an anteroseptal myocardial infarction complicated by an apical aneurysm. The clinical course was followed up by myocardial and cavitary scintigraphy. Coronary arteriography was carried out after convalescence and showed proximal occlusion of the left anterior descending artery and an apical aneurysm on ventriculography. Myocardial infarction after electrical injury is a rare event and its pathogenesis remains controversial. Although electrical currents can damage the walls of the coronary arteries, they may also have a direct thrombogenic effect. This would appear to be the most probable mechanism in the case reported in which the myocardial lesions corresponded to acute occlusion of the left anterior descending artery, perhaps favoured by the presence of an atheromatous plaque. Coronary arteriography was the most helpful investigation in assessing the physiopathology of this rare event.