The aim of this study was to evaluate the survival benefit of palliative gastrectomy for gastric cancer patients with peritoneal seeding proven intraoperatively and to identify positive predictive factors for improving survival.The value of palliative resection for gastric cancer patients with peritoneal metastasis is controversial.From 2006 to 2013, 267 gastric cancer patients with intraoperatively identified peritoneal dissemination were retrospectively analyzed. Patients were divided into resection group and nonresection group according to whether a palliative gastrectomy was performed. Clinicopathologic variables and survival were compared. Subgroup analyses stratified by clinicopathologic factors and multivariable analysis for overall survival were also performed.There were 114 patients in the resection group and 153 in nonresection group. The morbidities in the resection and nonresection groups were 14.91% and 5.88%, respectively (P = 0.014). There, however, was no difference in mortality between the 2 groups. The median survival time of patients in the resection group was longer than in nonresection group (14.00 versus 8.57 months, P = 0.000). The median survivals among the patients with different classifications of peritoneal metastasis were statistically significant (P = 0.000). Patients undergoing resection followed by chemotherapy had a significantly longer median survival, compared with that of patients who had chemotherapy alone, those who had resection alone, or those who had not received chemotherapy or resection (P = 0.000). Results of subgroup analyses showed that except for P3 patients and patients with multisite distant metastases, overall survival was significantly better in patients with palliative gastrectomy, compared with the nonresection group. In multivariate analysis, P3 disease (P = 0.000), absence of resection (P = 0.000), and lack of chemotherapy (P = 0.000) were identified as independently associated with poor survival.Palliative gastrectomy might be beneficial to the survival of gastric cancer patients with intraoperatively proven P1/P2 alone, rather than P3. Postoperative palliative chemotherapy could improve survival regardless of operation and should be recommended.