Klinefelter’s Syndrome is usually characterized by 47 XXY genotype, hypogonadism, tallness and infertility. In the literature it is estimated that 64% of Klinefelter’s Syndrome is undiagnosed and many patients have variety of psychiatric disorders. In this case report, we present a 17-year-old Klinefelter’s Syndrome patient who had been hospitalized because of multiple impulsive suicidal acts. Our aim is both to review the psychiatric presentations of this syndrome and to emphasize the importance of impulsivity and suicidal acts, which might be etiologically related with X-chromosome anomalies.