Background Advances in treatment of congenital heart disease (CHD) have resulted in most patients surviving to adulthood. Despite surgical “correction,” the need for reoperation(s) persists, and there are few outcome data. This study examined early postoperative results to determine risk factors for cardiac injury and early death in adults with CHD undergoing repeat median sternotomy. Methods Data from the most recent median sternotomy of 984 adults (49% male) with CHD were analyzed. Mean age at operation was 36.4 years. Diagnoses were conotruncal anomaly, 361 (37%); Ebstein/Tricuspid valve, 174 (18%); pulmonary stenosis/right ventricular outflow tract obstruction, 92 (9%); single ventricle, 71 (7%); atrioventricular septal defect, 64 (7%); subaortic stenosis, 62 (6%); aortic arch abnormalities, 23 (2%); anomalous pulmonary vein, 21 (2%); Marfan syndrome, 14 (1%); and other, 102 (10%). Results Overall early mortality was 3.6%: including 2%, 6%, 7%, and 0% at sternotomy 2 (n = 597), 3 (n = 284), 4 (n = 72), and 5+ (n = 31), respectively. Cardiac injury occurred in 6%. Independent predictors of cardiac injury were single-ventricle diagnosis and increased number of prior sternotomies. Increased time from previous sternotomy decreased the incidence of cardiac injury. Independent risk factors for early death were urgent operation, single-ventricle diagnosis, and longer bypass time. Increased preoperative ejection fraction decreased early mortality. Conclusions Subsequent sternotomy showed increased early mortality, yet neither sternotomy number nor cardiac injury was an independent predictor of early death. Two variables were protective: early mortality was reduced with increased ejection fraction and cardiac injury was less likely with increased interval from the previous sternotomy.