A 67-year-old man with an autopsy-proven ventricular septal defect (VSD) following an acute inferoposterior myocardial infarction underwent bedside evaluation by radionuclide imaging techniques. The presence of the VSD was confirmed, and the size of the shunt determined by qualitative and quantitative radionuclide angiocardiography. In addition, radionuclide ventriculography permitted assessment of global as well as regional left ventricular function.