Aim: To investigate the role of surgical resection of primary tumor on overall survival (OS) in advanced gastric cancer patients at the time of diagnosis. Patients & methods: The survival rates of metastatic gastric cancer patients whose gastric primary tumor was resected at time of diagnosis were compared with metastatic gastric cancer patients whose primary tumor was nonresected. Results: The median progression-free survival and OS in operated and nonoperated group were 10 versus 6, 14 versus 9 months, respectively (p < 0.001). In multivariate analysis, gastric resection of primary tumor, Eastern Cooperative Oncology Group performance status, second-line chemotherapy had a significant effect on OS (hazard ratio [HR]: 0.52 [95% CI: 0.38-0.71], HR: 0.57 [95% CI: 0.42-0.78], HR: 1.48 [1.09-2.01]; p <= 0.001, p = 0.001 and p = 0.012, respectively). Conclusion: Subpopulations of patients with metastatic gastric cancer might benefit from surgical removal of primary tumor.