Purpose: The aim of this study was to compare the clinicopathological characteristics and postoperative prognosis of two age groups with gastric cancer in order to establish the proper treatment strategy in these groups of patients. Materials and Methods: Among patients with gastric cancer who underwent a gastrectomy between 1990 and 1996 at the Department of Surgery, Kyungpook National University, the clinicopathological characteristics, including the postoperative survival, of patients younger than 40-years old were compared with those of patients over 69-years old. Results: During that period 1,125 gastric cancer patients underwent a gastrectomy. Among them, 111 patients ($9.9\%$) were less than 40-years old, and 96 patients ($8.5\%$) were over 69-years old. In the young group, 79 patients ($71.2\%$) had a poorly differentiated adenocarcinoma, and 59 patients from the elderly group ($61.5\%$) had a well- or moderately differentiated adenocarcinoma (P<0.05). Curative surgery was performed for 88 ($79.3\%$) patients in the young group and 78 ($81.3\%$) patients in the elderly group. This difference was not statistically significant. There was no statistically significant difference in the 5-year survival rates between the young and the elderly ($66.3\%;vs.;47.2\%$) groups, but the 5-year survival rate of the young group was significantly higher than that of the elderly group after a curative resection ($83.2\%;vs.;53.3\%$; P<0.05). Also the 5-year survival rate of the elderly group was significantly higher than that of the young group after a non-curative resection ($20.4\%;vs.;4.6\%$; P<0.05). Conclusions: For young patients, more efforts are needed to detect gastric cancer in its early stages so that a curative surgery can be performed. However, for the elderly, surgical treatment is recommended at any stage because of the relatively high survival rate, even after non-curative surgery.