Objective To identify the relationship between preoperative left ventricular dysfunction and perioperative risk factors in coronary artery bypass grafting (CABG). Methods The clinical data of 192 patients who underwent CABG from November 2015 to October 2016 were analyzed retrospectively. The patients were divided into three groups by preoperative left ventricular ejection fraction (LVEF) in echocardiography: a serious left ventricular dysfunction group (LVEF≤35%, 23 patients, 15 males and 8 females at age of 63.91±5.36 years), a moderate left ventricular dysfunction group (35%<LVEF<50%, 24 patients, 20 males and 4 females at age of 66.29±6.03 years) and a normal left ventricular function group (LVEF≥50%, 145 patients, 86 males and 59 females at age of 66.60±6.41 years). Results The overall mortality was 4.16% (8/192), 17.39% (4/23) in patients with LVEF≤35% and 2.76% (4/145) in those with LVEF≥50%. Preoperative LVEF≤35%, hypoxia, assisted circulation, acute kidney injury (AKI) and postoperative continuous renal replacement therapy (CRRT) were risk factors of perioperative mortality in coronary artery surgery. LVEF≤35% and CRRT were independent preditors of mortality. There were significant differences in mortality and postoperative complications between the serious left ventricular dysfunction group and other two groups. Conclusion Postoperative mortality and complications are obviously serious in the patients with LVEF≤35%. We should pay more attention to preoperative risk factors. Postoperative individual manipulation, intra-aortic balloon pump and CRRT can enhance survival of those patients.