With an aging population and an alarmingly increasing rate of colorectal cancer, the number of octogenarians undergoing surgery for colorectal cancer in Singapore is increasing. The aim of the study was to determine the immediate and long-term outcomes of surgery on octogenarians with colorectal cancer. Between April 1989 and November 1996, 2 211 patients with newly diagnosed colorectal cancer operated on in the department were entered into a computer database. Of these, 213 (9.6%) were above the age of 80 (range 80–100)years; 150 (70.4%) patients underwent potentially curative resections while 57 (26.8%) had palliative procedures. Postoperatively 22 (10.3%) patients had to be monitored in surgical intensive care units. Of the patients 18 (8%) had Dukes A while 68 (32%), 70 (33%) and 57 (27%) had Dukes B, C and D, respectively. The median follow-up period was 29 months (range 2–88). The median hospital stay was 16 days (range 4–64). The perioperative mortality was 11 of 213 (5.2%), and 59 of 213 (29%) developed perioperative complications. At the last follow-up 110 (51.6%) patients were alive without recurrence, while 5 (2.3%) had local recurrence and 2 (0.9%) distant disease; 96 patients had died, 28 (29.2%) from cancer-related causes. In conclusion, octogenarians have a higher risk usually because of associated medical diseases. However, surgery can be performed with acceptable mortality and morbidity risk. Furthermore, one half of the patients will be able to continue to the end of their lives free from disease.