Background Coexistent carotid and coronary artery diseases are common and patients with them remain at a high risk for perioperative stroke or myocardial infarction after coronary bypass surgery.The aim of this study was to investigate the effect of combined carotid endarterectomy (CEA) and off-pump coronary artery bypass grafting (CABG) in patients with coexistent carotid and coronary artery diseases.Methods Between January 2002 and December 2007, consecutive patients with coexistent carotid and coronary artery diseases underwent one-stage unilateral CEA and off-pump CABG in Heart institute of Nanjing First Hospital Affiliated to Nanjing Medical University. Perioperative complications were assessed and follow-up was carried out. Results A total of 51 cases of isolated off-pump CABG and unilateral CEA, including 34 right and 17 left, were performed. The mean blocked time of carotid artery in CEA was (25.5±7.0) minutes. The mean number of distal grafts per patient was 3.30±0.45. The mean ventilation time, intensive care unit stay, and postoperative hospital stay was (11.3±5.4) hours, (2.1 ±0.9) days, and (12.5±6.1) days respectively. None of the patients had stroke or myocardial infarct. There was one perioperative death due to acute cardiac failure, resulting in an operative mortality of 1.96%. Follow-up was completed for 47 patients (92.16%) with a mean follow-up of (39.5±12.5) months. None of the patients manifested stroke, new angina or newly developed cardiac infarct. No late death occurred.Conclusion Combined CEA and off-pump CABG is a safe and effective procedure in selected patients with coexistent carotid and coronary artery diseases.