Over a 3-year period 128 boys had endoscopic video recording; 29 were found to have a localized constriction of the bulbar urethra. Three had significant narrowing, 11 had a moderate change in lumenal diameter, and 15 had a minor indentation. Three boys had a membranous obstruction, 21 had a lesion that changed appearance during the endoscopy, consistent with contracting muscle, and 5 (all minor abnormalities) had a constriction of uncertain nature. Four also had an additional, more proximal membrane in the posterior urethra. Of the 23 boys with a Cobb's collar who had a urethrogram preoperatively, 18 were found to have an indentation in the bulbar urethra, separate from the external sphincter, which correlated in position with the cystoscopic findings. Most of the bulbar urethral lesions were incidental findings, which may represent either a muscular or fibrous remnant of the urogenital diaphragm.