The study was aimed to investigate the association between the degree of oligozoospermia and sperm chromosome aneuploidy frequencies in male infertility and to determine whether chromosomal profiles of sperm nuclei would be used for a supportive test before additive reproduction technics. The meiotic segregation profiles of chromosomes X, Y, 13, 18 and 21 were compared by fluorescent in-situ hybridisation (FISH) on the spermatozoa of 30 normally karyotyped oligozoospermic (10 mild, 11 moderate, nine severe) cases without Y-microdeletions, and 10 normozoospermic cases. The results showed significantly higher frequencies of chromosomes 13, 18, 21 disomies (P < 0.001) in the group of patients with moderate and severe oligozoospermia compared with the disomy frequencies of normozoospermic group. The statistically significant differences were also determined in disomy frequencies of sex chromosomes (XY, XX and YY) in between oligozoospermic and normozoospermic groups (P < 0.001, P < 0.001, P < 0.040, respectively). Because oligozoospermic patients are the ones consulted the most for assisted reproductive techniques, identification of sperm aneuploidy rates in men could be considered as an appropriate supportive test before the reproductive implementations. Furthermore, the patients should be counselled with respect to genetic screening results for the potential risk of aneuploid embryo and pre-implantation genetic diagnosis or prenatal diagnosis.