Sixty-eight patients operated upon for post-infarction VSD from 1980-1987 have been reviewed to identify incremental risk factors which influence survival. Univariate and multivariate analysis was performed on 19 parameters and showed the following in decreasing order of importance to be significantly associated with non-survival: (1) operation within 24 h of occurrence of the VSD; (2) inferior infarct preceding the VSD; (3) requirement for inotropic support preoperatively; (4) preoperative cardiogenic shock; (5) a lower mean pulmonary artery pressure; (6) a lower mean wedge pressure; (7) a lower mean systolic pressure. The presence of a graft to the right coronary artery was associated with a better prognosis. Age, sex, diastolic blood pressure, balloon pumping, mean plasma urea, right atrial pressure, extent of coronary disease, number of coronary grafts, grafts to the left coronary system and method of myocardial preservation had no influence on survival.