Twelve cases of gastric cancer in youths under 30 years of age were investigated clinically and histologically.They accounted for 1.96% of all operative cases of gastric cancer in the same period. Male/famale ratio was 2:1. As for the region of gastric cancer, lower third and middle third (region A and M) were common. Fifty percent of the tumors were early gastric cancers. Seven patients had stage I, and five stage IV cancers. The resection rate was 91.7% and the curative resection rate, 58.3%. Histologically, as high as 58.3% of them were poorly differenciated type, which was lower than the figures reported by other researchers. As for the initial symptoms, epigastralgia was predominant. The prognosis was good in stage I cancers received curative resection. Among patients undergone noncurative resection, three patients died of peritoneal recurrence. The mean survival time was 2 years and 2 months. Only one patient is still healthy without any recurrences, although he was in stage IV. We concluded that aggresive surgical resection would make the prognosis of stage IV patients better.