This report describes the case of a patient who developed acute myocardial infarction with ST segment elevation in anterior and inferior leads, simultaneously. After treatment with systemic thrombolysis, and after an initial short-lasting symptomatic improvement, chest pain and ST segment elevation recurred. Coronary angiography revealed severe complex stenotic lesions at both the right coronary artery and the left anterior descending (LAD) coronary artery. Percutaneous coronary angioplasty and stent implantation were successfully performed at both lesions. This case supports the concept that, at least in some patients, acute coronary artery disease reflects a diffuse pathophysiologic process that may lead to multifocal plaque instability associated with clinical instability at multiple sites.