Undetectable prostate-specific antigen was found in three aging men de
spite the absence of any prostatic surgery or exogenous hormonal depri
vation. Clinical and elementary hormonal workup revealed the presence
of secondary hypogonadism. This finding confirms the hormonal dependen
cy of this prostatic marker and may, in some cases, explain the discre
pancy between prostatic volume and the value of serum prostate-specifi
c antigen.