Objective: To explore the impact of iron deficiency on perioperative outcomes of patients undergoing coronary artery bypass grafting (CABG). Methods: A total of 284 patients who underwent CABG in the Department of Cardiovascular and Large Vascular Surgery of the First People’s Hospital Affiliated to Shanghai Jiao Tong University from January 2015 to December 2017 were included. According to the serum ferritin and transferrin saturation levels, they were divided into an iron deficiency group and an iron sufficiency group. The perioperative data were collected and the risk was adjusted by using PSM. The mortality rate, the incidence of major cardiovascular and cerebrovascular adverse events and related complications during perioperative period were analyzed. Results: All the 68 patients were enrolled into iron deficiency group. Compared with the iron sufficiency group, the iron deficiency group was composed of more aged patients, more females, and more anemic patients. After PSM, there was no statistical difference in in-hospital mortality (6.3% vs 1.1%, P=0.083) and major adverse cardiovascular events (6.3% vs 5.4%, P=0.844) between the two groups. Among the secondary observation end points, the postoperative drainage volume in the iron deficiency group [(952±497) mL vs (796±307) mL, P=0.041] was significantly increased, but the differences in the remaining end points were not statistically significant. Conclusion: The patients underwent CABG with iron deficiency showed lower hemoglobin level and consisted of more elders and females. But iron deficiency appears to have little impact on the perioperative outcomes of CABG patients except for increased postoperative drainage.