The operative morbidity and its relating factors were studied on 95 patients, 80 years old or older, operated for gastrointestinal (GI) diseases under general anesthesia at the department in a recent 11-year period. Among a total of 98 cases of GI diseases including 32 of gastric cancer, 17 of colorectal cancer, 16 of cholelithiasis and 33 of others, 108 procedures were performed for 38 gastric, 27 colorectal, 31 hepato-biliary-pancreatic and 12 other surgical conditions. Fifty-four operative complications occurred in 39 cases(41%), which were 13 respiratory, 11 delirium, 9 cardiovascular and 21 other complications. The respiratory morbidity rate was significantly high in males and significantly low in the cases receiving halanced epidural anesthesia. Postoperative delirium occurred more frequently in patients having an intraoperative blood loss of over 200 ml, and the cardiovascular morbidity rate was significantly high for an operative time of over 3 hours. The operative morbidity and 30-day operative mortality rate were significantly higher for emergency operations than for non-emergency operations. These findings suggest that, in the surgery for elderly patients and especially in an emergent situation, special care must be paid to decrease the quantity of bleeding and shorten the duration of operation by employing a proper procedure and anesthesia.