At the turn of the millennium, the authors summarize the evolution of a clinician's duty to protect third persons from a patient's violent acts over the past half century, with special emphasis on jurisprudential developments in the last decade. Four evolutionary periods are identified: Pre-Tarasoff, Inception, Diversification, and Retreat. The period of Retreat from Tarasoff in the nineties is characterized by the following approaches to Tarasoff: adoption, statutory containment, rejection of a duty to warn, rejection of a duty to control voluntary patients, and proactive circumscription of any protective duties. A more rational jurisprudential approach would permit some measure of flexibility for the proper exercise of clinical discretion.