Objective — to assess the effects of human granulocytic anaplasmosis (HGA) caused by Anaplasma phagocytophilum on the frequencies of karyopathological abnormalities in the blood cells and the levels of teratozoospermia depending on the GSTM1 gene polymorphism of glutathione-S-transferase. Material and methods. 30 healthy donors and 39 HGA male patients were involved in this study. There was no mixed infection in the HGA patients and their diagnosis was confirmed by enzyme immunoassay and polymerase chain reaction (PCR). Samples of both semen and peripheral blood were obtained from each individual to prepare cytological smears and to detect the deletion polymorphism of GSTM1 gene (GSTM1 (0/0) or GSTM1 (+)) by PCR. Results. Cytological analysis revealed teratozoospermia with higher levels of several types of both head and neck spermatozoa abnormalities in the HGA patients as compared to the control group (p<0.01). The levels of teratozoospermia in the patient carriers of GSTM1(0/0) allele were significantly higher than in the patients with the normal allele GSTM1(+) (p<0.01). In HGA patients, it was detected increased frequencies of blood cells with the following various types of karyopathologic abnormalities as compared with the control: erythrocytes with micronuclei (MN); monocytes with MN, chromatinolysis, fragmentation, binucleation, karyorexis, perinuclear vacuoles; neutrophils with hypersegmentation, fragmentation and chromatinolysis of the nucleus (p<0.01). The highest frequency of micronucleated monocytes and erythrocytes was found in the subgroup of GSTM1(0/0) carriers among the HGA patients (p<0.01). Significant positive correlations between the frequencies of abnormal heads of spermatozoa and the levels of blood cells with various types of karyopathologic aberrations (p<0.01 or p<0.05) were revealed in the HGA patients. Conclusion. In HGA patients, particularly in patients with GSTM1 (0/0) deletion genotype, there were revealed not only the significant increased levels of teratozoospermia and karyopathological abnormalities in the blood cells, but there was also positive association between these indices compared with the healthy group.