The study objective is to evaluate the significance of the Y chromosome microdeletions for prediction of spermatozoa retrieval during testicle biopsy in men with severe azoospermia and oligozoospermia.Materials and methods. In total, 109 men aged 21 to 56 years (mean age 32.7 ± 0.2 years) with infertility in marriage were examined. Cytogenetic, special andrological, spermiological, and molecular genetic examinations were performed to evaluate non-genetic and genetic causes of infertility.Results. Normal karyotype and absence of AZF deletions were found in 75 men, presence of deletions – in 34. The frequencies of pathozoospermia forms were comparable in these groups. Spermatozoa were retrieved during biopsy in 47 (62.7 %) patients without Y chromosome microdeletions and only in 7 (20.6 %) patients with Y chromosome microdeletions. The men with AZF deletions were divided into 2 subgroups: men with complete AZF region deletions (n = 25) and men with partial AZF deletions (n = 9). Among men with complete deletions, azoospermia was diagnosed in 25 (100 %), spermatozoa were retrieved during biopsy in 2 (8 %); among men with partial deletions, azoospermia was diagnosed in 7 (77.8 %), severe oligozoospermia in 2 (22.2 %), spermatozoa were retrieved during biopsy in 5 (56 %). Then the patients were divided according to another criterion: 54 patients from whom spermatozoa were retrieved during biopsy and 55 men with negative results. Among patients with successful result of biopsy, Y chromosome microdeletions were identified in 7 (13 %); among patient with negative biopsy result – in 27 (49 %) (р < 0.01).Conclusion. Success rate of spermatozoa retrieval during testicle biopsy is significantly higher in men without AZF deletions (р < 0.01) than in men with deletions. Molecular genetic examination of Y chromosome microdeletions is recommended for men with azoospermia and severe oligozoospermia because it allows diagnosing of cause male infertility and predicting.