Over the past decade former, and sometimes current, adversaries in the Middle East increasingly have been engaged in unofficial multilateral regional security dialogues, a form of track two diplomacy. Despite the proliferation of such dialogues, we know very little about them. This article reviews the nature and content of a variety of track two security dialogues among Arabs and Israelis and evaluates the impact of such activities. What have such dialogues accomplished to date, and what are their limitations? By what standards should we measure success and failure? How can such dialogues be improved in the Middle East and other conflictual regions? The article suggests that those who expect track two to lead to major policy shifts in track one (the official negotiating process) will be disappointed and perceive such dialogues as a failure. However, if we evaluate track two based on what the process itself produces, both in terms of changing regional perceptions among its participants and impacting regional security policy in an incremental fashion, we are more likely to see its value. In this sense, the research supports arguments made by other students of negotiation who suggest that outcomes are not always the sole objective or the appropriate measure of success for international negotiations; the negotiation process itself also has value. Despite problems and limitations, track two diplomacy has proved an important mechanism in building regional understanding and knowledge in the arms control and regional security realm. Such diplomacy could also be applied to other issues and regions during the lengthy process of building peace among adversaries.