Introduction: Sex chromosome abnormalities such as Klinefelter Syndrome (XXY) and Yacobs Syndrome (XYY), are characterized by tall stature and infertility in adulthood, being associated with a higher risk for neurodevelopmental, behavioral and cognitive phenotypes. The aim is to study the neuro-genetic aspects in patients with chromosomal variations in male infertility, in order to achieve an early diagnosis and preventing complications. Material and methods: A group of 95 men with infertility were cytogenetically investigated by the classique G-banding technique, having as selection criteria, azoospermia, increased or normal values of FSH (follicle-stimulating hormone) and LH (luteinizing hormone), the following phenotypic aspects: tall stature, hypogonadism, cryptorchidism, gynecomastia, mental retardation, hyperactivity, impulsivity, psychosocial problems. The statistical processing of the data was carried out using the SPSS program (Statistical Package for the Social Sciences) version 22.0. Rezults: According to the cytogenetic results, Klinefelter syndrome was confirmed in 10 (10.5%) cases: of which in 9 cases the classic form 47,XXY- 90.9% and one case the mosaic form 47,XXY/46,XY: - 9.1 %. In 2 (2.1%) cases, Yacobs Syndrome was identified with the cytogenetic variant 47,XYY. Patients with both chromosomal abnormalities presented lack of spermatozoa in the ejaculate, hypogonadism, behavioral and psychiatric problems, among which in SK: mild to moderate mental retardation; language disorders with cognitive-verbal retardation, slow motor development, coordination disorders, immature behavior and in Yacobs Syndrome: impulsivity, emotional lability, hyperactivity. Patients with XXY reported increased values of FSH hormone (20.2±8.7 mIU/ml, (95% CI: 14.3-26.1; median 19.2) and LH 19.5±7.3 mIU/ ml, (CI 95%: 14.6-24.4; median 21.5), patients with XYY endocrine marker values within normal limits. Conclusion: The evaluation of the phenotypic psycho-behavioral characteristics of the 47,XXY and 47,XYY Syndromes in early childhood will contribute to their early diagnosis and will allow the initiation of appropriate treatment and, respectively, the prevention of possible complications as well as the minimization of the negative psycho-social impact.