Twenty consecutive patients with postinfarction ventricular septal defect (VSD) were subjected to surgery: there were 8 females and 12 males with a mean age of 67 +/- 9 years. Nine acute patients developed cardiogenic shock, and intra-aortic balloon pump was started before surgery (with IABP). Eight acute patients showed preoperatively relatively stable hemodynamics, and surgery was feasible without previous use of the intra-aortic balloon pump (without IABP). The interval between myocardial infarction and surgery was 13 days for 17 acute cases. In the group with IABP the interval was 8 +/- 5 days versus 19 +/- 11 days in the group without IABP (p less than 0.025). VSD patch closure was performed in 20/20, resection of infarct in 10/20, transventricular approach without resection of infarct in 3/20, patch enlargement of the left ventricle in 2/20, plicature of an aneurysm in 3/20, aorto-coronary bypass in 10/20 (number of bypasses: 2.1 +/- 1.3) and mitral annuloplasty in 1/20. The perioperative 30 days mortality was 5/20 (25%) for the whole series. In the group with IABP mortality was 4/9 (44%) versus 1/8 (13%) in the group of acute patients without IABP (p less than 0.05). Mean follow-up for the 15 surviving patients was 1.7 +/- 1.0 years. Two patients died during the first year, one of them due to carcinoma. After 1 year, mean NYHA functional class was assessed 1.5 +/- 0.6. One patient showed a residual VSD which was closed surgically. Immediate closure of a postinfarction ventricular septal defect is the therapy of choice of this complication of acute myocardial infarct with a natural history showing an extremely high mortality.