Background Total mesorectal excision (TME) has been reported to reduce local recurrence and improve survival rates in patients with rectal carcinoma. This paper reports the problems that have arisen with the introduction of this new surgical technique. Methods This was a prospective study of two consecutive groups of patients: one who underwent TME (n = 76) and one who did not (non‐TME, n = 76). Results Postoperative mortality rate in the non‐TME and TME group was 5 and 7 per cent respectively, and the rate of anastomotic failure was 8 and 16 per cent respectively. Anastomotic leaks in TME patients were located in the mid and lower rectum. TME patients with anastomotic failure had lower anastomoses and a longer duration of operation than non‐TME patients. Intraoperative problems were encountered in 71 per cent of the failures. All TME patients who had a leak required reoperation compared with 25 per cent of non‐TME patients. TME patients without postoperative complications stayed significantly longer in hospital than non‐TME patients. Conclusion Anastomotic dehiscence increased after introduction of the TME technique but this improved with experience. © 1998 British Journal of Surgery Society Ltd