Abstract: This essay aims to examine the psychopatology in sex criminals. The literature about the subject was reviewed. According to the literature, crime is regarded as a kind of deviation from the legitimate social norms of society. On the contray, punishment is a response to a crime or offense that is the act of inflicting a consequence or penalty on someone as a result of their wrongdoing, or the consequence or penalty itself. The execution of the punishment depends on the penal institutions where the liberty binding punishments are enforced upon arrest warrants. It may be accepted that the life in penal institutions is one of the most crucial life events creating stress. Penal conditions could trigger the psychological problems such as depression, anxiety, impulse control disorders, adjustment disorders, etc. All mental disorders influences social life which take a person away from the joy of living, make him/her unhappy, uneasy and unproductive because of the psychological and somatic indications. It is proved that there is a relationship between sex crime and mental disorders, based on the relevant scales. The sex criminals reliably show high-level psychopathology. The rate of depression and anxiety disorders with the adult and child sex criminals is higher than the normal population.