Patients with gastric cancer aged 70 years or over were divided into 3 age groups (70-74, 75-79, 80 years or over) and were compared with patients aged 60-69 years, (which is the age group with the highest incidence of stomach cancer) with regard to the incidence of postoperative complications. In addition, factors which might be associated with increased mortality were investigated. There were no significant differences with regard to the incidence of postoperative complications (16-21%) or the mortality rate (0-3%, within 30 days after surgery) between the various age groups. However, the incidence of those complications which later proved fatal was higher in those aged 75 years or over. Factors associated with the development of complications in each age group were the type of surgical technique used, the operation time, and the severity of hemorrhage during surgery. The prognosis for gastric resection was poor in patients aged 80 years or over. Our findings indicated that curative resections should be performed for gastric cancers in the elderly if the general physical condition of the patients permits. A more conservative approach is desirable when the general condition is not favorable.