Over the past six years there has been a 15-fold increase in the number of patients requiring reoperation coronary artery bypass grafting (RCABG) surgery at the University of Alabama in Birmingham. To determine the perioperative risk, a retrospective chart survey of one calendar year's (198J) experience was made comparing the 58 RCABG patients with 59 cohorts undergoing primary operation. All patients were anaesthetized with diaze-pam, fentanyl and halothane or enflurane anaesthesia. Preoperative evaluation revealed by history that the incidence of unstable angina and digoxin use were greater (p = 0.05) in the RCABG patients. Cardiac catheterization revealed a higher incidence (26 vs 89 percent) of left main coronary disease in controls and similar indices of left ventricular function (wall abnormalities, ejection fraction and LVEDP). Operating and bypass times were longer (p < 0.01) for RCABG patients and there was a trend for greater (p = 0.08) use of dopamine in the RCABG patients. CK-MB release was significantly (p < 0.05) greater in RCABG patients. Serious postoperative complications (CK-MB ≥ 15IU/L, low cardiac output, and death) were significantly (p = 0.02) greater in the RCABG group, his concluded that RCABG patients représenta greater risk of complications and that new strategies for improving my ocardial protection need to be developed to reduce the risk. © 1984 Canadian Anaesthesiologists.