Objective To explore the risk factors of perioperative complications of radical gastrectomy for gastric cancer. Methods A retrospective study was conducted on 1 580 patients with gastric cancer who underwent radical gastrectomy in our hospital from Jan. 2016 to Dec. 2018. The demographic information, preoperative clinical data, operative information, postoperative pathological data and complications of the patients were recorded, and the complications were graded by Clavien-Dindo grading. Pearson χ² test was used to evaluate the relationship between the perioperative complications and clinicopathological characteristics. Multivariate logistic regression was used to analyze the independent risk factors of perioperative complications. Results Of the 1 580 patients, 134 (8.48%) had perioperative complications. Anastomotic complications are the most common complications (44 cases, 2.78%), including 34 cases (2.15%) of anastomotic leakage, 7 cases (0.44%) of anastomotic bleeding, and 3 cases (0.19%) of anastomotic stenosis, followed by pancreatic leakage (27 cases, 1.71%) and chylous leakage (19 cases, 1.20%). Seventeen patients (1.08%) had complications with ClavienDindo grade ≥ Ⅲa. Univariate analysis showed that age ≥ 70 years (P=0.012), underlying diseases (P<0.01), preoperative prognostic nutritional index<38 (P=0.033), extent of resection (P=0.036), reconstruction mode (P<0.01), intraoperative blood loss ≥ 300 mL (P<0.01) and number of removed lymph nodes<25 (P=0.026) were associated with perioperative complications in gastric cancer patients. Multivariate logistic regression analysis showed that underlying diseases (odds ratio[OR]=1.964, 95% confidence interval[CI] 1.231-3.133, P=0.005) and intraoperative blood loss (OR=1.002, 95% CI 1.001-1.003, P<0.01) were the independent risk factors of perioperative complications in gastric cancer patients. Conclusion In gastric cancer patients with underlying diseases and large intraoperative blood loss, it is necessary to pay attention to perioperative symptoms and signs to avoid the development of complications.