Abstract: Synchronous multiple gastric cancer is a rare condition involving multiple malignant tumors at different sites in the stomach. Such cases account for 6%-14% of all gastric cancers. Currently, cases of multiple gastric cancer can be classified by the monoclonal or polyclonal nature of the original tumor. Some patients with multiple gastric cancer exhibit hereditary susceptibility and mutations in mismatch repair genes. Multiple gastric cancer occurs more commonly among elderly male patients and in the proximal stomach at an early stage. No significant differences in vascular invasion, differentiation status, and lymph node metastasis have been identified between solitary and multiple gastric cancers. Several treatment approaches for multiple gastric cancer have been applied clinically, including endoscopic resection and subtotal and total gastric resection according to the tumor stages and sites. Further discussion is needed regarding the extension of gastric resection for multiple gastric cancer in patients with hereditary susceptibility.