Introduction: Infertility is a significant multifactorial disorder that can be caused by chromosomal abnormalities. In this study, we aimed to cytogenetically investigate male and female patients admitted to the Genetic Diagnostic Laboratory of Kayseri Educational Hospital in Kayseri, Turkey with varied clinical prediagnoses of infertility. Materials and Methods: Chromosomes from cultured peripheral blood lymphocytes of 274 patients and 427 individuals as the controls were analyzed using GiemsaTrypsin-Giemsa (GTG) banding. The individuals with sex chromosome aneuploidy or mosaicism were classified as carriers and with chromosomal polymorphism, respectively. The results of the two groups were compared statistically. Results: Pure sex chromosome aneuploidy was found in 29 (10.5%) patients and mosaic sex chromosome aneuploidy in 15 (5.5%) cases and the total rate of abnormalities was 16%. Karyotypes were composed of an overall polymorphism rate of 8% in the patient and 4% in the control groups with no statistically significant difference (p = 0.2 and p > 0.05, respectively). Conclusion: The present study shows that chromosomal polymorphisms are common among infertile patients. Chromosomal abnormalities and even heteromorphisms are significant etiologic factors leading to fertility problems. The overall high prevalence of chromosomal polymorphisms in infertile couples, compared to the normal population, needs to be confirmed with further investigations and larger study populations to delineate the role of “harmless” chromosomal aberrations in the etiology of infertility.