Infertility is a polyetiological disease and requires modern universal markers, studying of which could allow determination of the appropriate tactics of treatment of patients with impaired fertility, evaluation of prognosis, and prospects of treatment. Besides, there is an evident trend towards widening of indications to apply auxiliary reproductive technologies in treatment of patients with the most serious factors of male infertility. Inhibin, that is a hormone composed of two subunits, may act as one of such markers that allow judging of the morphological and functional state of the testicular parenchyma. Inhibin B that is produced with Sertoli cells and young spermatogenous cells in the seminiferous tubules is a known endocrine marker for evaluation of spermatogenesis. The review includes analysis of results of the studies that investigated the value of determination of the level of inhibin B in the course of diagnostics of male infertility as well as in the course of prognosis of results of testicular sperm extraction. It has been demonstrated that on the whole inhibin B is a more sensitive marker than the follicle-stimulating hormone. According to a number of authors, due to its high sensitivity and specificity, inhibin B may become the alternative to testicular biopsy, as well as a marker of differential diagnosis of male infertility in future. At the same time, the level of inhibin B in serum may not be used as a singular marker of males with non-obstructive azoospermia. Ambiguous results received require further studies.