Thirty-two male patients with mechanical or functional bladder outlet obstruction were treated by bilateral endoscopic bladder neck incision. In three cases a repeat incision was necessary. Subjective cure or improvement was obtained in 81%. Objective evaluation, including uroflowmetry and residual urine measurements, showed a similar improvement. Bladder neck incision takes only a few minutes, is simple and less traumatic than transurethral resection. The aetiology of impaired micturition and the value of urodynamic assessment are discussed and some attention devoted to the problem of post-operative retrograde ejaculation.