Objective To evaluate the influence of the high body mass index (BMI) on the postoperative common complicating infections in the patients with primary liver cancer. Methods Six databases including Pub Med, web of science, EMBASE, Co chrane, CNKI and Wanfang Data Knowledge Service Platform were retrieved by computer to collect the retrospective cohort studies of the postoperative common complicating infections in the patients with primary liver cancer who had high, low or normal BMI. The meta analysis was carried out by adopting the Rev Man 5.3 software, and the publication bias was detected by Begg's method in the Stata 12.0 software. Results Six articles were included, which all were from the Asia area, and the study subjects totaled 2082 cases. The postoperative common complicating infection incidence rate had no statistical difference between the patients with high BMI and the patients with low or normal BMI (RR = 1.18, 9 5 % CI : 0.6 9-2. 02, P = 0.55); the incidence rates of postoperative complicating wound, pulmonary and intra abdominal infections had no statistical difference between the patients with high BMI and the patients with low or normal BMI (RR= 1.18, 0.89, 2.19; 95 %CI: 0.78-1.79, 0.49-1.64, 0.4 7-10.16; P = 0.43, 0.71, 0.32). The Begg and Egger's test indicated that the publication bias was small without significant bias. The sensitivity analysis showed that the RR value did not exceed the 95 %CI range of the merged RR value, suggesting that the results of this study were reliable. Conclusion High BMI may not be a risk factor of the common complicating infections after operative resection in the patients with primary liver cancer. [ABSTRACT FROM AUTHOR]