Background: Urinary and sexual dysfunction are recognized complications of rectal excision for cancer. The aim of this study was to examine the frequency of such complications after mesorectal excision, shortly after this method was introduced. Methods: Spontaneous flowmetry, residual volume of urine measurement and urodynamic examination, including cystometry and simultaneous detrusor pressure and urinary flow recording, was carried out before and 3 months after curative rectal excision. Urinary symptoms and sexual function were evaluated by means of questionnaires before and after operation. Each patient served as his or her own control. Results: Forty‐nine consecutive patients, 39 of whom had a total mesorectal excision (TME) and ten a partial mesorectal excision, were examined before surgery and 35 again after operation. In two patients, a weak detrusor was detected before operation. Two patients developed signs of bladder denervation after operation. Transitory moderate urinary incontinence appeared in four other women. Six of 24 men reported some reduction in erectile function and one became impotent. Two men reported retrograde ejaculation. All the complications were seen in the TME group. Conclusion: Mesorectal excision for rectal cancer resulted in a low frequency of serious bladder and sexual dysfunction. © 2000 British Journal of Surgery Society Ltd