Background. Statin therapy prior to coronary artery bypass surgery (CABG) has been shown to prevent perioperative events such as myocardial infarction and perioperative death. The effect of statin therapy as a preventive treatment to decrease the stroke risk unrelated to cardiac surgery is also documented. In the setting of CABG, we have found no studies reporting a preventive effect of statin therapy on neurologic outcome. Methods. We analyzed 6,813 patients treated by CABG surgery at our institution between 1995 and 2005 for which complete medication history including all drugs taken before and after surgery was available. We analyzed the risk factors for postoperative stroke using a multiple logistic regression analysis, more specifically looking at the effect of preoperative treatment with statin, aspirin, beta-blockers, and angiotensin-converting enzyme inhibitors, alone or in combination. Results. At 30 days postoperative, 94 patients suffered a new documented stroke (1.4%). Hypertension, carotid disease, diabetes, and age were all associated with a greater risk of postoperative stroke. When analyzing the four groups of drug therapy, none of the medications alone affected the stroke rate. However, upon multivariable analysis the combination of statin and beta-blockers gave an odds ratio of 0.377, suggesting a strong protective effect. Conclusions. Beta-blockers combined with statin confer a protective effect for stroke after CABG. (Ann Thorac Surg 2011;91:654-60) (C) 2011 by The Society of Thoracic Surgeons