We prospectively studied bladder and urethral function in 44 patients before and after abdominoperineal resection of the rectum for ano-rectal cancer. The patients were investigated with the following examinations: combined cystometry and electromyography, urethral pressure profile measurement, urecholine denervation test, urine culture, urethrogram and residual urine measurement after voiding. Urodynamic results after surgery demonstrated the partial or total denervation of the detrusor muscle with bladder areflexia in the 54% of the cases, the decrease in the urethral pressure profile in the 48% of the cases, and the absence of detrusor sphincter dyssynergia in all cases. Urethrogram results showed a high incidence of bladder dislocation into the presacral space (36%). Urine cultures were frequently positive in 52% of the patients. Most patients (52%) had difficulty in voiding with high residual urine and/or stress incontinence (4.5%). All the patients received an early rehabilitative treatment with kinesitherapy and/or pharmacologic therapy after bladder catheter removal and after urodynamic results. The patients with neurogenic bladder with residual urine volume had satisfactory functional recovery of the activity.