Background. Stroke complicates the postoperative course in 1% to 6% of patients undergoing coronary revascularization. There has been no large scale mandatory database reporting on the incidence of stroke after coronary revascularization. Methods. A multicenter regional database from the Bureau of Health Care Research Information Services, New York State Department of Health, on 19,224 patients who underwent coronary revascularization in 31 hospitals within New York State during 1995 was analyzed to determine the risk factors for postoperative stroke. Results. The incidence of postoperative stroke was 1.4% (n = 270). Hospital mortality for patients who had a stroke was 24.8%, compared with 2.0% for the rest of the patient population. Postoperative stroke increased the hospital length of stay threefold (27.9 ± 1.9 versus 9.1 ± 0.9 days, p < 0.0001). Multivariable logistic regression identified the following variables to be significantly associated with a postoperative stroke: calcified aorta (p < 0.0001; odds ratio [OR], 3.013), prior stroke (p = 0.0003; OR, 1.909), age (p < 0.0001; OR, 1.522 per 10 years), carotid arterial disease (p = 0.002; OR, 1.590), duration of cardiopulmonary bypass (p = 0.0004; OR, 1.27 per 60 minutes), renal failure (p = 0.0062; OR, 2.032), peripheral vascular disease (p = 0.0157; OR, 1.62), cigarette smoking (p = 0.0197; OR, 1.621), and diabetes mellitus (p = 0.0158; OR, 1.373). Conclusions. Postoperative stroke increases mortality and length of stay after coronary revascularization. Several risk factors can be identified, and some of these factors are potentially amenable to intervention, either before or during coronary revascularization, and should also influence patient selection. (C) 2000 by The Society of Thoracic Surgeons.