A prospective study of 570 patients presenting with colorectal cancer over a 6-year period was undertaken. Of these, 363 were admitted electively and 207 presented as emergencies. The outcome following elective admission was more favourable than after emergency admission. In the elective group the proportion of resected tumours was greater (77 versus 64 per cent, P less than 0.001), the operative mortality rate lower (9 versus 19 per cent, P less than 0.001) and the 5-year disease-related survival rate higher (37 versus 19 per cent, P less than 0.001). These differences may relate to the greater resection rates in the elective situation. Results of surgical intervention might be improved if emergency colorectal operations were undertaken by surgeons with more experience of this type of surgery.