The overall purpose of this article is to present a review of the literature that identifies the salient ethical guidelines related to the practice of supervision and to discuss the results of a study that examined supervisor ethical practices. In terms of our investigation, we examined supervisee perceptions of their supervisors' adherence to ethical guidelines, supervisee reactions to ethical violations, and the relationships among supervisor ethical behaviors, the supervisory working alliance, and supervisee satisfaction. The results indicated that 51% of the 151 beginning to intern-level supervisees sampled reported at least one ethical violation by their supervisors. The most frequently violated guidelines involved adequate performance evaluation, confidentiality issues relevant to supervision, and ability to work with alternative perspectives. Greater nonadherence to ethical guidelines was significantly related to a weaker supervisory alliance and lower supervisee satisfaction. Limitations and implications for psychotherapy supervision theory, research, and practice are addressed.Although the mental health field has long recognized the importance of ethical standards for the practice of counseling and psychotherapy (e.g., American Psychological Association, 1992), only recently has attention been focused on the importance of ethical standards for counseling and psychotherapy supervision (