Recent experience suggests that ventricular septal defect (VSD) secondary to myocardial infarction constitutes an indication for urgent operation. Acquired VSD at St. Thomas Hospital, Nashville, was reviewed to substantiate the obsolescence of protracted medical therapy designed to allow a late, technically less demanding, repair. Twenty-two acute VSDs (less than four weeks following onset of murmur) have been treated since 1970. Five patients died during medical therapy. Two patients survived for more than four weeks without operation. One never manifested significant cardiac decompensation. The other was operated on at 33 days, after progressive deterioration. No technical advantage from the delay was apparent, although survival was achieved. Ten of 15 patients (67%) operated on during the first four weeks survived. Fourteen had reached a level of marked instability prior to operation. Of the five deaths, four were technical and were the product of an initial lack of recognition of the necessity for patch replacement of the interventricular septum. The prosthetic patch is now considered essential to minimize suture-line stress in necrotic muscle. Potentially, only one of 15 patients operated on early using current methods would have expired. This experience supports an aggressive surgical approach to any unstable patient with postinfarction VSD. Early repair requires specific techniques. Results of early operation using these techniques are dramatically superior to past efforts designed to delay definitive repair.