The value of preoperative assessment in relation to outcome and long-term survival was studied in 171 octogenarians undergoing major gastrointestinal surgery at Dumfries and Galloway Royal Infirmary between 1985 and 1990. The 30-day mortality rates for elective and emergency operations were 11% and 25% respectively. The American Society of Anesthesiologists (ASA) physical status scale was found to be a useful predictor of morbidity and mortality. ASA class 2 patients had a postoperative complication rate of 36% and a mortality rate of 13% while the figures for ASA class 4 patients were 85% and 54% respectively. Cox proportional hazards survival analysis using the variables age group, sex, ASA class, and type of surgery showed that the only statistically significant differences were between ASA classes. The relative 5-year survival of 63% indicates that these patients compare favourably with a population of the same age and sex not undergoing an operation. These data suggest that in the absence of severe concomitant medical disease, gastrointestinal surgery can be carried out reasonably safely in the elderly.