This is a review of 31 patients with ventricular septal rupture occurring in myocardial infarction which have been managed at the Singapore General Hospital. Ventricular septal rupture occurs more frequently in the elderly, in females and those presenting with the first myocardial infarction. Very few have a prior history of stable angina pectoris before the myocardial infarction. Sudden deterioration as manifested by an increase in heart rate, fall in blood pressure and signs of right heart failure in a patient with acute myocardial infarction (AMI) especially if accompanied by a systolic murmur should encourage a search for a mechanical cause, especially a ventricular septal rupture. 2D echocardiography or Swan-Ganz catheterisation are 100% diagnostic and can be easily and rapidly done at the bedside. Medical management includes vasodilator therapy and inotropic support. Intra-aortic balloon counterpulsation is especially useful and was instituted in 6 patients. Early surgical repair of the ventricular septal defect is important if overall prognosis of these patients is to be improved. Our operative survival of 42.9% is comparable to others, considering that without surgery all have died. Survival appears to be related to the site of the myocardial infarction (very poor prognosis in inferior myocardial infarction), operative treatment (no survivors if treated conservatively) and the mode of presentation (poor prognosis in patients who develop a ventricular septal rupture while in hospital).