False aneurysms of the left ventricle were repaired in four patients (average age, 61 years). The etiology was myocardial infarction in three patients and disruption of an apical left ventricular cannulation site in the fourth. The interval from initiating event to surgery averaged 11 months. One patient was in cardiogenic shock and succumbed in the operating room from myocardial failure. The other three patients, in functional class III at the time of surgery, survived and are currently asymptomatic. The literature records 43 patients who have undergone surgical repair of a false aneurysm of the left ventricle. The causes were myocardial infarction (12 patients), operative injury (13 patients), penetrating trauma (11 patients), and blunt trauma (seven patients). Twenty-seven (63%) were under the age of 50 years. In those who were limited by symptoms, congestive heart failure predominated. Forty seven per cent of the patients were operated upon in the first five months following the initiating event; 61% within the first year. Only four patients underwent surgery more than 48 months after the myocardial insult. Thrombus was present in 28% of the aneurysms. Morbidity was recorded in nine patients, and six patients (14%) died. This study documents the necessity for early surgical repair and the relatively low operative mortality obtained with this lethal lesion.