Real-time, two-dimensional echocardiographic studies were performed in 10 patients with acute myocardial infarction who had clinical features suggestive of right ventricular involvement. All patients showed right ventricular wall motion abnormalities. In the four-chamber view, 7 patients showed akinesis of the entire right ventricular diaphragmatic wall and 3 showed akinesis of segments of the diaphragmatic wall. Segmental dyskinetic areas involving the right ventricular free wall were identified in 4 patients. One patient showed a large right ventricular apical aneurysm. Other echocardiographic features included enlargement of the right ventricle in 8 cases, paradoxical ventricular septal motion in 7 cases, tricuspid incompetence in 8 cases, dilatation of the stomach in 4 cases and localized pericardial effusion in 2 cases. Right ventricular infarction was confirmed by radionuclide methods in 7 patients, at surgery in 1 patient and at autopsy in 2 patients.