BACKGROUND Patients requiring coronary artery bypass grafting (CABG) and carotid endarterectomy (CEA) can be managed with staged (CEA before CABG), reverse staged (CABG before CEA) or synchronous treatment. This single-center retrospective study evaluated the outcomes in patients undergoing planned synchronous CEA and CABG. METHODS Between 2000 and 2020 a total of 185 patients with symptomatic triple-vessel or left main coronary artery disease associated with 70-99% asymptomatic or 50-99% symptomatic uni- or bilateral internal carotid artery (ICA) stenosis underwent synchronous CEA and CABG at our institution. Study endpoints were defined as mortality, stroke and myocardial infarction at 30 days. Additionally, the composite endpoint of these events was investigated. RESULTS At 30 days, mortality, stroke and myocardial infarction rates were 5.9%, 8.1% (permanent [unresolved deficit at discharge] 5.4%) and 3.8%, respectively, and the composite endpoint was reached in 13.0% of patients. Patients suffering from a stroke more frequently had a contralateral 70-99% ICA stenosis (60.0% vs. 17.3%; p < 0.001), peripheral artery disease (73.3% vs. 38.9%; p = 0.013) and prolonged cardiopulmonary bypass time (mean 119 ± 62 min vs. 84 ± 29 min; p = 0.012). Multivariate logistic regression analysis revealed the duration of cardiopulmonary bypass (odds ratio [OR] 1.024; 95% confidence interval [CI] 1.002-1.046; p = 0.034), a history of type 2 diabetes mellitus (OR 5.097; 95% CI 1.161-22.367; p = 0.031) and peripheral artery disease (OR 5.814; 95% CI 1.231-27.457; p = 0.026) as independent risk factors for reaching the composite endpoint. CONCLUSIONS Patients undergoing synchronous CEA and CABG face an elevated risk of perioperative cardiovascular events, particularly an increased stroke risk in patients with symptomatic and bilateral ICA stenosis. Graphical Abstract available for this article.