The jurisprudence on a clinician's duty to protect third parties is complex and continues to evolve. Clinicians should familiarize themselves with civil commitment laws, privilege and confidentiality statutes, protective disclosure statutes, reporting requirements, and the Tarasoff Principle, as they would case law in the state in which they practice. Ethical codes and ethical position statements provide useful guidance. In their practices, clinicians should endeavor to conduct careful assessments for diagnoses, the patient's current situation, and dangerousness. Traditional clinical, therapeutic, and instructional measures should always be considered first, and reasonable efforts should be made to enlist the patient's cooperation. Occasionally, however, hospitalization or protective disclosures must be made. The proposed algorithm should be of help to the clinician in making critical decisions regarding hospitalization and disclosures to protect others. In following this decision tree, four questions are of key importance: (1) Is the patient dangerous to others?; (2) Is the danger due to serious mental illness?; (3) Is the danger imminent?; and (4) Is the danger targeted at identifiable victims? This algorithm is intended to assist in the application of, and should not replace, clinical judgment.