A new standardized technique for continuous recording of the urethral pressure profile simultaneously with intravesical pressure has been developed. The pressures are recorded using two microtransducers enclosed in a thin Dacron catheter. The catheter is moved at a constant speed through the urethra with the aid of a specially designed withdrawal instrument. Using electronic subtraction the closure pressure can easily be measured simultaneously with the intravesical and intraurethral pressure. About 900 investigations have been performed with this technique. It has been testified that very detailed information about normal micturition as well as stress and urgency incontinence can be obtained. The functional as well as the absolute length of the urethra can be estimated within half a millimeter.