Three patients are presented in whom a false aneurysm of the left ventricle was surgically treated. False aneurysm of the left ventricle is an unusual consequence of ventricular wall rupture with containment of the resulting hematoma. Most false aneurysms of the left ventricle develop following myocardial infarction. The false aneurysm wall contains no myocardium. The false aneurysm has a great tendency to rupture, regardless of its size. One patient developed progressive congestive heart failure following a myocardial infarction. The other two patients were asymptomatic following myocardial infarction. Preoperative magnetic resonance imaging showed characteristics of a false aneurysm. These included a distinct discontinuance of the myocardium at the neck of the aneurysm and a narrow neck relative to the diameter of the aneurysm. Two patients underwent successful closure of the orifice of the false aneurysms. One patient underwent emergency surgery because of acute rupture while awaiting surgery but died of cerebral damage. Surgical correction of a false aneurysm is clearly advisable even in the absence of symptoms.