A look at the legal issues involved in informed consent to treatment notes that listing the elements of informed consent poses no problem, but that the application of these elements to particular patients and situations is much more difficult. An analysis of the offender's right to refuse treatment examines this right as it applies to mental patients, inmates, and aggressive sexual offenders. Both legal and ethical issues in treating aggressive sexual offenders are reviewed including surgical treatment (castration and psychosurgery) and behavior modification techniques, primarily aversive techniques and token economies. Ethical issues involved in serving patient and institutional societal interests are categorized as (1) honesty in informing all parties about the interests and needs of others involved, (2) therapists' recognition of their superior power relative to their patients, and (3) therapists' confidentiality regarding their patients. The resolution or open recognition of these issues is recommended through treatment agreements between therapist and patient. Thirty-eight references are listed.