Objectives : The current study investigated the personality characteristics of the sexual offender using the Minnesota Multiphasic Personality Inventory (MMPI) test commonly used in clinical medicine. Methods : 30 sexual offenders (30 male) completed the Korean version of the MMPI. 20 of the 30 sexual offenders were patients with paraphilia. The sexual offenders had been admitted to the Institute of Forensic Psychiatry Ministry of Justice, Gongju, for sexual violence. Results : The MMPI scores of the sexual offenders were significantly higher on the psychopathic deviate (Pd), masculinity-feminity (Mf), paranoia (Pa), psychasthenia (Pt), schizophrenia (Sc) than the comparison group. And The MMPI scores of the sexual offenders had higher values for hypochondriasis (Hs), depression (D), hysteria (Hy), hypomania (Ma), social introversion (Si) than the comparison group, but were not significantly higher. Conclusion : Sexual offenders may be antisocial, paranoid, schizoid or psychasthenic. They seem to have psychotic psychopathology rather than neurotic psychopathology. These results suggested that the psychopatholgy of sexual offenders may be different to the control group.