Thirty patients with chest pain syndromes were studied on admission by two-dimensional echocardiography (2DE) to confirm or exclude acute myocardial infarction (AMI). Twelve patients suffered nontransmural AMI and 18 patients had no AMI. There was no significant difference between these groups in background characteristics. 2DE studies were analyzed quantitatively and qualitatively. The most sensitive and specific technique for detecting AMI was qualitative analysis, using the presence of severe hypokinesis as the criterion for an abnormal study. Using this technique, 10 of 12 patients (83%) with AMI and all 18 patients (100%) without AMI were correctly identified. This analysis technique was highly reproducible. These data indicate that in patients with chest pain syndromes without diagnostic ECG findings of AMI, 2DE may provide a rapid, sensitive, specific tool to aid in the establishment of the correct diagnosis. In patients with nontransmural AMI, the presence of severe hypokinesis appears to be the best discriminator of myocardial infarction.