The morphology of ventricular premature complexes (VPCs) is useful in detecting old or recent myocardial infarction. Rarely, however, have VPCs provided the first objective evidence of transmural myocardial infarction. In two patients with chest pain, VPCs early in the hospital course revealed myocardial infarction, while normally conducted sinus beats showed no evidence of acute transmural infarction. Transmural infarction with total occlusion of a large coronary artery was confirmed angiographically. We conclude that acute transmural myocardial infarction may be diagnosed early and accurately from VPC morphology before the appearance of other evidence of infarction.