Objective: To investigate the risk factors and prognosis for peritoneal metastasis in gastric cancer. Methods: The clinicopathologic data of 352 patients with gastric cancer were retrospectively analyzed. Results: The peritoneal metastasis rate of the entire group was 15.1% (53/352). Univariate analysis showed that gastric cancer peritoneal metastasis was related to the sex, histological types, depth of stomach wall invasion, lymph node metastasis, TNM stage, surgical procedure and local recurrence (all P<0.01). Multivariate analysis revealed that the depth of gastric wall invasion (P=0.016, 95%CI=0.570–0.945), TNM stage (P<0.001, 95%CI=2.414–4.027), lymph node metastasis (P=0.027, 95%CI=1.041–1.964), surgical procedure (P<0.001, 95%CI=1.203–1.870) and local recurrence (P<0.001, 95%CI=1.376–2.871) were risk factors for gastric cancer peritoneal metastases. The 1- and 2-year survival rates in patients with peritoneal metastasis were 44% and 10%, which in patients without peritoneal metastasis were 97.0% and 74.0% respectively, and the difference between the survival rates of the two groups had statistical significance (χ2=249.411, P<0.001). Conclusion: Gastric cancer with peritoneal metastasis predicts the high malignancy and poor diagnosis of the tumor. The depth of gastric wall invasion, TNM stage, lymph node metastasis, surgical procedure and local recurrence are independent significant risk factors for gastric cancer peritoneal metastasis.