This study utilized a state-wide data base containing clinical risk factors for cardiac surgery to investigate differences in in-hospital mortality rates for men and women undergoing coronary artery bypass surgery. The crude mortality rates for coronary artery bypass surgery for men and women were 3.08% and 5.43% respectively, in New York State in 1989. When logistic regression analysis was used to control for preoperative risk, gender remained a significant predictor of mortality. Risk-adjusted (indirectly standardized) mortality rates were 3.33% and 4.45% for men and women, respectively. The risk-adjusted odds ratio of women to men experiencing in-hospital death was 1.52 (95% confidence interval 1.25 to 1.90).