We describe 3 patients with an initial diagnosis of myocardial infarction, in whom a definitive diagnosis of myocarditis was subsequently established. All had precordial chest pain, electrocardiographic changes, elevated cardiac enzyme levels and regional wall motion abnormalities of the left ventricle compatible with myocardial infarction. During follow-up, all symptoms subsided and electrocardiographic tracings normalized. Regional wall motion abnormalities disappeared in two and persisted in one patient. These findings show that myocarditis may mimic myocardial infarction, and that the definitive diagnosis is generally established retrospectively.