PURPOSE: To identify risk factors for mortality after postoperative myocardial infarction. METHOD: Retrospective study of 266 patients. RESULTS: The crude in-hospital mortality rate was 25%. This was more than twice as high as the mortality rate in patients admitted from home with an acute myocardial infarction. Women with postoperative infarction were the same age as men, but had a lower Acute Physiology and Chronic Health Evaluation (APACHE) II score prior to infarction (P = 0.03) and a higher crude mortality rate. Multivariate analysis showed that female gender (relative risk 2.2, 95% confidence limits 1.2 to 4.2), current cigarette smoking (relative risk 2.3 [1.2 to 4.7]), a history of congestive heart failure (relative risk 2.1 [1.04 to 4.1], resuscitation status (relative risk 8.1 [2.0 to 32.9]), and high preoperative APACHE II score were significant independent predictors of in-hospital mortality. CONCLUSION: Postoperative myocardial infarction is one of the most serious events a patient can experience. Women and current smokers are at especially high risk for mortality after postoperative myocardial infarction. (C) 1997 by Excerpta Medica, Inc.