PURPOSE: Gastric cancer is the most common cancer in Korea, occurring in 20.8% of all cancer patients, most frequently at the antrum, followed by the body and fundus. Multiple synchronous gastric cancers are reported in 0.8 to 8.3% of all gastric cancers. This study aimed to investigate their clinicopathological features and prognosis. METHODS: Out of 6068 patients that underwent a gastrectomy for gastric cancers at the Department of Surgery, Samsung Medical Center between September 1994 and December 2002, 108 multiple synchronous gastric cancers patients, with more than two lesions, were investigated using a clinicopathological evaluation. RESULTS: The mean age of the subjects was 59.8 years with a male to female ratio of 4.68: 1. The majority of subjects had two lesions , but some had as many as five. A subtotal gastrectomy was performed in 67 and a total gastrectomy in 41 cases. Early stage and advanced gastric cancers were present in 164 and 68 patients, respectively. Fifty-four patients had multiple lesions only at an early stage, 10 at an advanced stage and 44 at both stages. The average tumor sizes of the main and secondary lesions were 39.1 and 23.5 mm, respectively. The lesions were mostly located in the lower two-thirds of the stomach, with 54 having different regions for the main and accessory lesions; one in the each of the upper, middle and lower regions, and seven in the upper and lower regions only. The overall five year survival rate was 89.8%. CONCLUSION: With the generalization of an endoscopic diagnosis, gastric cancers can be diagnosed more quickly and accurately. Despite the rare occurrence of multiple synchronous gastric cancers, the possibility of further lesion, especially in early gastric cancers, should be considered.