THE USUAL APPROACH TO DEFINING SEX OFFENDERS IS TO IDENTIFY THOSE PATIENTS CONVICTED OF A SEXUAL OFFENSE RESULTING IN ADMISSION TO A SPECIAL HOSPITAL EITHER DIRECTLY FROM THE COURTS OR INDIRECTLY FROM OTHER PSYCHIATRIC HOSPITALS OR THE PENAL SYSTEM. THIS LEGAL DEFINITION ACCOUNTS FOR 10 PERCENT OF ADMISSIONS, BUT SINCE A FURTHER 11 PERCENT HAVE A HISTORY OF SEXUAL OFFENDING, THE LEGAL DEFINITION SHOULD BE BROADENED. SEXUAL MISBEHAVIOR IS A REASON FOR ADMISSION IN 16 PERCENT OF THE CASES, AND 27 PERCENT OF THOSE ADMITTED WERE THOUGHT BY THEIR CONSULTANTS TO HAVE HAD SOME DEGREE OF SEXUAL MOTIVATION UNDERLYING THEIR OFFENSE. ONCE THE DEFINITION AND IDENTIFICATION OF SEXUAL OFFENDERS HAVE BEEN AGREED UPON, THE IMPLICATIONS FOR THERAPY AND DISCHARGE CAN BE FULLY ASSESSED. THE UNIQUENESS OF THE SPECIAL HOSPITAL POPULATION IS ALSO A PROBLEM, WITH FEW COMPARISON GROUPS AVAILABLE AND FEW DESCRIPTIVE STUDIES DONE ON SEX OFFENDERS, PARTICULARLY IN THE UNITED KINGDOM. ALSO, THE BULK OF THE EXISTING LITERATURE IS CONCERNED WITH RAPE, WHEREAS CONVICTIONS FOR INDECENT ASSAULT ON A FEMALE OR BUGGERY OR ATTEMPTED BUGGERY ARE FAR MORE COMMON OCCURRENCES. ANOTHER FACET OF THE EXCLUSIVENESS OF THE POPULATION IS THE PREVALENCE OF SEX CONVICTIONS IN THE CRIMINAL HISTORIES OF SEX OFFENDERS. SPECIAL HOSPITAL PATIENTS CONVICTED OF BUGGERY OR RAPE HAVE MORE CONVICTIONS FOR THESE SPECIFIC OFFENSES THAN DO OTHER TYPES OF SEX OFFENDERS WHICH RESULTS IN A POPULATION QUITE DIFFERENT FROM OTHER SEX OFFENDER POPULATIONS. FURTHER STUDIES ARE REQUIRED TO PROVIDE INFORMATION ON HOW PATIENTS CAME TO BE CONSIDERED BOTH SEX OFFENDERS AND DANGEROUS AND HOW THESE SPECIAL HOSPITAL PATIENTS COMPARE TO SIMILAR MEN WHO ARE NOT SEX OFFENDERS. RESEARCH SHOULD ALSO FOCUS ON THE EFFECTS OF BEING LABELED A SEX OFFENDER AFTER PATIENTS ARE DISCHARGED. TABLES SUPPLEMENT THE TEXT.