The present paper describes a test center which permits urodynamics tests with the patient in various positions, such as lithotomy position (A), supine position with outstretched legs (B) and, by continuously raising the patient, upright position (C). The results of a comparative investigation show the influence of these different examination positions on urodynamic parameters, in particular the functional length of the urethra and maximum urethra closing pressure at rest. Urodynamic tests on 40 patients with urinary incontinence showed that there is a significant increase in the functional length of the urethra when the patient is in lithotomy position (A) as compared to lying with outstretched legs (B), and that it is once again significantly reduced when the patient is raised to upright position. Maximum urethra closing pressure at rest drops significantly when the patient is repositioned from lithotomy (A) to supine (B) position, and once again rises significantly when she is raised to the upright (C) as compared to the supine (B) position. In the light of the changes described, which cause major changes in the form of the urethra pressure profile, it makes sense to perform urodynamic measurements in at least two different positions. The authors recommend the supine position with outstretched legs (B), as it appears more physiological than the lithotomy position (A), and measurement in the upright position (C). The importance of positioning with regard to the diagnostic information value in determining the cause of urinary incontinence is discussed.