Operative procedure and clinicopathological features were studied in patients undergoing emergency operation for colorectal cancer. Subject were 29 patients with intestinal obstruction due to colorectal cancer and 10 patients with perforated colorectal cancer out of 290 patients operated on for colorectal cancer at the department from 1980 to 1991. In a comparison with patients undergoing elective operation, no significant difference was noted in age, sex, histological type, and macroscopic morphology, however, there was a tendency to have deeper invasion depth into the wall or to have other organ metastasis in emergency ones. Emergency operation cases were commonly in an advanced stage at the onset of the disease. That might be a probable reason for its lowered incidence of curative resection. However, if curative resection could be performed in emergency cases, the 5-year survival rate of them did not significantly differ from that of elective operation cases. The prognosis was not necessarily poor for even emergency operation cases. Some cases were capable of undergoing radical operation. Pre and intraoperative correct diagnosis and appropriate selection of operative procedure would promise some emergency cases a favorable prognosis of the same length as that of elective operation cases.