Although perineal ultrasound has been widely used, no standard values have been published. In 52 women with urinary stress incontinence the following parameters were measured during resting and straining: a) with ultrasound: distance (Dy) between bladder neck and central line of the symphysis, distance (Dx) between bladder neck and lower border of the symphysis, and retrovesical angle beta; b) with urethrocystography (UCG): distance H between the bladder neck and the SCIPP line, inclination angle alpha and retrovesical angle beta. Dy and H correlated during resting ( r = 0.608; p<0.001) and straining ( r = 0.575; p<0.001). The distance Dy of 11 mm corresponded to a bladder neck position on the SQIPP line. A rotational descent was detectable when Dx increased from 13 mm (+/- 6.5) during resting to 16 mm (+/-7.8) during straining ( p=0.009). It was concluded that perineal ultrasound is valuable for the anatomical evaluation of the bladder neck. This is the first report to better define the position of the bladder based on ultrasonographic measurements.