Thirteen patients with intraventricular septal rupture in the course of acute myocardial infarction (AMI) have been examined with simultaneous cross-sectional echocardiography (CSE) and Doppler ultrasound. Visualization of the rupture was achieved in six patients by CSE alone. The simultaneous technique identified the rupture in all patients. Eight patients were operated upon; seven of them are still alive. We conclude that simultaneous CSE and Doppler ultrasound is a sensitive, rapid and safe technique for diagnosing ventricular septal rupture (VSR) after AMI.