OBJECTIVE To determine the clinical, symptomatic and objective urodynamic outcome of patients undergoing endoscopic bladder transection. METHODS The study included 20 men and 30 women (mean age of 50 +/- 15 years, range 20-86) who underwent endoscopic bladder transection. Their underlying diagnoses were idiopathic detrusor instability (41), enuresis with instability (6), multiple sclerosis (2) and Parkinson's disease (1). A full-thickness endoscopic transection of the bladder was performed under general anaesthesia. Subjective assessment was performed using symptom scores (0-14 points) and a Visick grading system (group A-E). Objective assessment was carried out using urodynamic studies. The mean follow-up period was 6 years (57 +/- 22 months, range 6-85). RESULTS The mean hospital stay was 8 +/- 3 days (range 3-22). No patients died after the operation. Postoperative complications included extra-peritoneal extravasation (2), recurrent urinary tract infection (5) and urethral stricture (1). Symptom scores before and after the operation were 9 +/- 2 (range 4-14) and 8 +/- 3 (range 1-14) points respectively. The overall outcome of the procedure was satisfactory in only eight (16%) patients. The mean duration of symptomatic relief was 17 weeks (range 3-53). There was no significant difference between urodynamic results before and after the operation. Bladder instability observed in all patients before operating was demonstrated in 93% of patients after the operation. CONCLUSIONS The results of our study suggests that endoscopic bladder transection produces only a transient symptomatic relief in a few of those patients who have failed to respond to pharmacological manipulations. We do not feel that its continued role is justified.