At the beginning of the 21st century there is a decline in quality of reproductive health of men around the world. In structure of sterile marriage the men's factor of infertility is found out in approximately 40-50% of cases. A little studied question of male infertility is the question of quantity and quality of gametes in convoluted seminiferous tubules. Aim: to study morphological (quantitative and qualitative) changes of a seminiferous epithelium of patients with male infertility. Materials and Methods: 264 patients with male infertility have been examined. Patients with an obstructive form of infertility, with diseases sexually transmitted, with varicocele, with the revealed genetic and immunological factors of infertility have not been included in the research. Patients with a heavy form of pathospermia (n = 112) were taken a testis biopsy before the ICSI cycle (Intra Cytoplasmic Sperm Injection). Further a condition of the seminiferous epithelium of a testis was estimated with the use of light microscopy. Results: Hypoplasy of a seminiferous epithelium was revealed around 34 (30,5%) men, subtotal aplasia of a seminiferous epithelium - around 59 (52,6%) patients, Sertoli Cell-only syndrome - around 12 (10,7%) and tubular atrophy of convoluted seminiferous tubules - around 7 (6,2% ) patients. Conclusions: The morphological research of testis gives the opportunity to define the extent of pathological process at all stages of a spermatogenesis. Only on the basis of studying of features of a spermatogenesis of the specific patient it is possible to make an algorithm of further personal medical and rehabilitation actions.