The level of urinary PSA (PSAu) was measured for use as a marker in some clinical situations involving prostate cancer patients. Limits of physiological and pathological values, a quantity of which comes from the urethral glands and the umbilical median ligament (urachus), are still unknown. To establish the quantity of PSA secretion in the urethra, female PSAu was measured and found to be significantly low (< 0.1 ng/ml). The Authors report on 25 PR patients with negative margins and who had not received hormonal therapy for 30 months. The PSAu and the PSAs were measured on the 30th and the 60th day, and every 3 months thereafter in the first year and every 6 months in the second year. In 5 cases we observed an increase of PSAu between the 5th and 18th months. In 3 cases the PSAs increased 2 to 6 months later compared to the PSAu. In these 3 cases the biopsy indicated the presence of a localized relapse. Therefore the Authors recommend measuring the PSAu (cut-off 0.1 ng/ml) in the follow-up of the PR patients because the measurement may both identify a localized relapse earlier than the PSAs and indicate the localized response to hormonal or radiotherapy.