The management of sexual delinquents, especially those with compulsive putting into action of aggressive sexual impulses, poses great problems for the medical profession from the therapeutic as well as the moral standpoint. In the past thirty years or so numerous different approaches have been tried with varying degrees of success. A much abridged list of more recent treatment procedures includes: surgical castration (Stürup, 1968), sedative and/or tranquillizer drugs (Litkey and Feniczy, 1967; Bartholomew, 1968), female sex hormones (Allen, 1970); psychological measures such as psychotherapy (Ellis, 1956; Mayerson and Lief, 1965; Allen, 1970) and/or behaviour (‘aversion’) therapy (MacCulloch and Feldman, 1967) and ‘right up-to-date’ hypothalamotomy (B.M. J., 1969). Unfortunately surgery, which is the most reliably effective of these treatments, may have unpleasant sequelae; its use, which (in Britain at least) is beset with ethical problems, is therefore justified in only the most recalcitrant and/or dangerous types of offender, and only then when other methods have failed.