The authors present the results of determination of the testosterone and androstendion excretion in the patients with various forms of hypogonadism and in healthy men. Testosterone excretion was decreased in the patients with hypogonadism, against the background of normal or increased androstendion excretion whereas the degree of deviations of the testosterone/androstendion ratio depended on the clinical variant of hypogonadism. Thus, retarded or decreased accumulation of the enzymes in the testes responsible for the change from the "child" to the "mature" type of steroid biosynthesis could serve as a mechanism of hypogonadism occurrence, which should be taken into consideration in the elaboration of the methods of syndrome therapy of this type of pathology.