We present an atypical case of postinfarction left ventricular pseudoaneurysm involving the posterobasal septal wall, with protrusion into the right ventricle, associated with a small septal defect and left-to-right shunt. In this case, a conservative approach was adopted rather than surgical management, and the patient had a good clinical outcome. Subsequent evaluation with two-dimensional colour Doppler, three-dimensional echocardiography and 16-slice computed tomography is reported.