Surgery was performed for postinfarction ventricular septal defect (VSD) in 25 consecutive patients (14 men, 11 women; mean age 68 +/- 8 years). 9 patients were preoperatively in cardiogenic shock and required mechanical circulatory support by intra-aortic balloon pump (IABP) before surgery, whereas 11 acute patients underwent surgery without use of the IABP beforehand. The following procedures were performed: VSD patch closure in 25/25 patients, resection of infarct in 15/25, and patch enlargement of the left ventricle in 3/25. The overall 30-day mortality was 6/25 (24%). However, mortality was higher (4/9 [44%]) in the group with IABP support versus the group of acute patients without it (2/11 [18%]: p less than 0.05). In patients with significant postinfarction VSD, surgical closure appears to be mandatory.