The number of CAG repeats of exon 1 of AR gene was determined in a group of 228 infertile males with azoospermia (n= 68) and oligozoospermia (n= 160) as well as in control group (124 proven fathers) by fluorescent polymerase chain reaction amplification followed by fragment analysis on automated fluorescent analyzer" ALF-express". The frequency of alleles with GAG-repeats< or= 18 was significantly higher (P< 0, 01) in the group of patients with azoospermia (17, 7%) comparing with the control group (2, 4%) as well as in the group of patients with oligozoospermia (12, 5%) comparing with the control group (2, 4%). The frequency of alleles with CAG-repeats> or= 28 significantly differed (P< 0, 01) between the group of patients with oligozoospermia (12, 5%) and the control group (2, 4%). Our data suggest an association between CAG repeats number and impaired spermatogenesis in azoospermic and oligozoospermic males.