Professional boundaries refer to the “edge” or limit of appropriate behavior in the clinical setting. The fundamental ethical principal involved is respect for the patient’s dignity and autonomy. Because there is a potential for exploitation of the patient due to the power differential and asymmetry between psychiatrist and patient, the following dimensions of the treatment frame must be considered: location, time, behavior, language, dress, confidentiality, self-disclosure, money and gifts, dual relationships, and physical/sexual contact. Context is crucially important in assessing professional boundaries. Hence, relatively benign boundary crossings must be differentiated from exploitative boundary violations. Preventive strategies, such as education, self-monitoring, and regular consultation should be part of the practice of all clinicians. The domain of the Internet is a recent context that has emerged, and psychiatrists must now be attuned to boundary issues in cyberspace.