ObjectiveTo summarize the influence and mechanism of visceral fat on the treatment and prognosis of gastric cancer patients.MethodLiteratures on the correlation and mechanism between visceral fat and treatment and prognosis of gastric cancer were collected and reviewed.ResultsHigh visceral fat may promote the incidence and progress of gastric cancer, and increase the incidence of complication of radical gastrectomy, including surgical site infection, pancreatic fistula, etc., as well as prolong the length of hospital stay. Reducing patients’ visceral fat level before operation could reduce the incidence of surgical complication. However, the persistent decrease of visceral fat level after operation may indicate poor prognosis. The effect of visceral fat on gastric cancer and its treatment was mainly due to the local chronic inflammation caused by excessive visceral fat tissue, the change of adipocytokine secretion, insulin resistance, and other mechanisms.ConclusionWe need to use visceral fat and other indicators to evaluate gastric cancer patients’ weight and body composition, in order to better guide the treatment and prognosis evaluation of gastric cancer.