Klinefelter syndrome (KS) 47, XXY is the most frequent chromosomal abnormality causing hypogonadism in humans. This chromosomal abnormality of number in its classical form called homogeneous (supernumerary X) is generally the result of a meiosis accident. Several studies have suggested that individuals with KS are at greater risk of developing various psychiatric disorders, including depression and schizophrenia. The diagnosis is made based on subnormal testosterone with high pituitary gonadotropins and confirmed by determining the karyotype on a blood simple. We did a literature review using an electronic search in three databases: Pubmed/MEDLINE, Google Scholar, and PsychInfo. We found that since 1989, seven case reports with KS and mental disorders with similar and different characteristics of our case illustration of a patient with KS and psychosis were published.