With the help of a prospective study of 100 patients, in whom an operation of the prostate was taken into consideration (TUR, adenomectomy, radical operation), the clinical value of the suprapubic sonography of prostate and urinary bladder is presented. The determination of the size of the adenoma and the residual urine is particularly dealt with. Clinical, transurethral and radiological examination methods served as reference methods, in addition to this the weight of the specimen. The study resulted in a high accordance between sonography and reference methods. The fully painless and undangerous suprapubic sonography and prostate and urinary bladder become an integrated constituent of the urological diagnostics and replaces a large part of hitherto performed transurethral examination methods.