While sexual interaction between psychologists, physicians, and other health therapists of all kinds and their clients is typically condemned by professional bodies as unethical, the controversy regarding the potential for hypnosis to produce compliant behavior in unwilling or nonconsenting subjects suggests that hypnotherapist-client sex may warrant special attention. Because the experiments required to clarify the potential for hypnosis to potentiate nontrivial compliance are themselves unethical and/or inconclusive, experimental methods cannot be adequately used to clarify this issue. Instead, the matter can be addressed by reference to other forms of evidence, such as the responses of therapists and clients to anonymous surveys and the analysis of cases, that have reached the courts. Consideration of this qualitatively deficient evidence suggests that even if the use of hypnotic suggestion can lead to compliance to sexual demands, overt coercion is seldom used in practice. Social psychological and situational factors are particularly salient in understanding therapist-client sex. The question of whether there are special properties of the dynamics of the hypnotic experience, other than specific coercive suggestion and beyond those typically found in other forms of therapy, is considered. Comparisons are drawn with other examples of socially condemned sex, such as teacher-student sex, sexual harassment in the workplace, incest, and extramarital sex.