Objective: To assess the incidence and independent risk factors for clinical anastomotic leakage (AL) in patients undergoing anterior resection (AR) or low anterior resection, (LAR) for rectal cancer. Methods: This was a retrospective case-control study of 550 patients with rectal cancer who underwent AR or LAR from April 2007 to March 2017 in Beijing Friendship Hospital, Capital Medical University. The relationship between the incidence of AL and clinicopathological manifestations was analyzed by Chi-squared test and Fisher exact test, and the independent risk factors of AL were analyzed using logistic regression analysis. AL is defined as a defect (including necrosis or abscess formation) of the intestinal wall at the anastomotic site, leading to a communication between the intra- and extra-luminal compartments. AL can be divided into three grades. Grade A anastomotic leakage results in no change in the management of patients, whereas grade B leakage requires active therapeutic intervention but is manageable without re-laparotomy. Grade C anastomotic leakage requires re-laparotomy. Results: AL was noted in 32 (5.8%) of 550 patients with rectal cancer who underwent AR or LAR, including 15 (46.9%) , 4 (12.5%) , and 13 patients (40.6%) with Grades A, B, and C, respectively. Five patients (0.9%, 5/550) died peri-operatively. AL- and non-AL-related deaths occurred in 3 (9.4%, 3/32, all cases were Grade C) and 2 patients (0.4%, 2/518) , respectively, with the two mortality rates being significant difference (P = 0.002) . Chi-squared test or Fisher exact test showed that the incidence of AL was associated with neoadjuvant chemoradiotherapy (P = 0.011) , intraoperative bleeding (≥100 ml) (χ² = 11.980, P = 0.001) , and tension-reducing suture of anastomosis (P = 0.015) . The results of logistic regression analysis showed that the independent risk factors of AL were neoadjuvant chemoradiotherapy (OR = 2.402, 95%CI: 1.004 - 5.749, P = 0.049) , intraoperative bleeding (≥100 ml) (OR = 2.971, 95%CI: 1.269 - 6.957, P = 0.012) and tension-reducing suture of anastomosis (OR = 2.304, 95%CI: 1.008 - 5.263, P = 0.048) . Conclusion The incidence of AL in patients undergoing AR for rectal cancer is 5.8%. The high-risk factors for AL are neoadjuvant chemoradiotherapy, intraoperative bleeding (≥100 ml) , and tension-reducing suture of anastomosis. Patients with these three risk factors have a high risk of AL rate, and a defunctioning stoma should be performed.