It is estimated that 15% of couples suffer from infertility worldwide, and the male factor is involved in half of the cases. Male infertility refers to a man's inability to conceive in a fertile woman. The basis of male fertility is the quality and quantity of semen. Thus, men who have sperm parameters below the normal values set by the WHO are considered to have infertility problems involving the male factor. There is an inverse correlation between sperm count and the prevalence of genetic abnormalities. About 15% of men with nonobstructive azoospermia and 4% of men with severe oligozoospermia have chromosomal abnormalities. The aim of this study is to evaluate the profile of chromosomal abnormalities and chromosomal polymorphisms in men with severe oligozooppermia and azoospermia in the population of the Republic of Moldova. The study included research on the cytogenetic results of men with oligozoospermia and azoospermia in the population of Moldova during the years 2013 - 2019. Patients come from infertile couples who addressed the National Center for Reproductive Health and Medical Genetics. The group of patients consists of men with 28 oligozoospermia and 148 azoospermia. All patients were cytogenetically investigated by the classical G-banding technique, on peripheral blood lymphocytes. Nomenclature according to ISCN (International System of Cytogenetic Nomenclature) 2016 was used to report the results. In 148 men with azoospermia 95 (64%) were identified normal karyotype 46, XY, variations in number or structure of chromosomes were found in 53 (36%). 42 patients (28%) were presented variations in the X or Y sex chromosomes, and 11 patients (8%) variations in the autosomal chromosomes. In the 42 azoospermic patients identified with sex chromosomal abnormalities, 31 cases were detected chromosomal number abnormalities and in 11 cases - structural variations. Among the number chromosomal abnormalities in 28 cases was aneuploidy X (Klinefelter Syndrome), 2 cases mosaic 45,X/46,XY and one case was identified with 46, XX karyotype in male. The structural variations of the sex chromosomes detected were in 8 cases duplications of the distal arm of the Y chromosome (Yqh+) and in 3 cases deletions of the distal arm of the same chromosome (Yqh-). In 28 men with oligozoospermia normal karyotype 46, XY were identified in 26 (93%) cases and 2 (7%) cases variations of the sex chromosomes. In this study, the incidence of chromosomal abnormalities that served as a cause for azoospermia was 36% and oligozoospermia 7%. According the high frequency of chromosomal abnormalities in infertile men, as well as the genetic risks for future generations, it is important to evaluate the profile of chromosomal abnormalities them before resorting to Assisted Reproduction Techniques such as ICSI (Intracytoplasmic Sperm Injection) and IVF (in vitro fertilization).