Transrectal linear array transducer makes possible a sagittal view of the bladder base-plate, prostatic urethra, and membranous urethra yielding an image similar to that obtained with voiding cystourethrogram. This permits lack of time limitation, such as imposed by the use of fluoroscopy, and the possibility of visualizing not only the lumen of the bladder neck and urethra but also the surrounding soft tissue. Using ultrasonographic urodynamics in neuromuscular dysfunctions of the bladder and urinary voiding obstructions we obtained excellent results in patients with detrusor-sphincter dyssynergia and in those with posterior ledge at the bladder neck. Both conditions are clearly visualized, particularly the existence of the posterior ledge which is responsible for the failure of the sphincterotomy in patients with periurethral striated sphincter spasm.