Study Type - Diagnostic (case series) Level of Evidence 4 What's known on the subject? and What does the study add? In the 1980s and 1990s, a method for direct measurement of pressure and cross-sectional area in women and men was developed. It was successful in terms of obtaining meaningful results in several studies. But the technique, which was based on the field gradient principle, was never implemented in the clinical setting because of technical limitations. In 2005, urethral pressure reflectometry was introduced as a new technique in female urodynamics. The technique has been shown to be more reproducible than conventional urethral pressure profilometry, when measuring incontinence in women. In 2010 it was also introduced as a new measuring technique in the anal canal. This study, adds a new and interesting technique to the field of male urodynamics. For the first time, sound waves have been used to measure pressure and cross-sectional area simultaneously, directly in the prostatic urethra. The results from this first trial with urethral pressure reflectometry are promising, in terms of obtaining meaningful physiological parameters. Our hope is that, future trials will help us to be able to identify specific areas of obstruction or rigidity in the prostatic urethra, making treatment more direct and side effects from surgery less severe. However, further studies are needed to evaluate the technique with regards to clinical usefulness in men with benign prostatic obstruction.