Seventy-seven octogenarian patients with gastric cancer (Group 1) were retrospectively investigated and compared with patients of age from 75 to 79 years (Group 2). The incidence rates for renal impairment, hepatic impairment, and hypoproteinemia, as preoperative complications, were higher in Group 1 than in Group 2 (each p < 0.05). The resectability rate was 83% in Group 1 and 89% in Group 2. D1 lymphadenectomy was performed for 45% of Group 1 and for 18% of Group 2 (p < 0.001). On the other hand, D2 lymphadenectomy was performed for 39% of Group 1 and for 71% of Group 2 (p < 0.001). A postoperative complication occurred in 25% of Group 1 and in 9% of Group 2 (p < 0.01). However, the postoperative mortality rate was zero in both groups. The t1 (early cancer) rate was 27% in Group 1 and 41% in Group 2 (p < 0.05). On the other hand, t2 was 31% in Group 1 and 19% in Group 2 (p < 0.05). The overall 5-year-survival rate was 38% in Group 1 and 48% in Group 2. When causes of mortality other than gastric cancer were excluded, the 5-year-survival-rate was 51% in Group 1 and 67% in Group 2 (p < 0.01).