Continuous and systematic analysis of ethical considerations is important in preserving the integrity of the process of conflict intervention and the intervenor's activities. Intervenors may act on behalf of one party, on behalf of a specific outcome or policy, or on behalf of a specific process for dealing with the conflict. Intervenors can help clients use existing knowledge to solve problems, create and apply new arrangements of existing knowledge, and jointly develop new conceptual models. The five distinct roles of intervenors are as activists, advocates, mediators, researchers, and enforcers. Each role expresses some form of advocacy and thus is open to ethical inquiries regarding base, intention, and impact. Intervention must rest on the principles of valuing all persons and therefore of empowering all groups, producing justice, and preserving freedom. These values have implications for both intervenor roles and intervenors' activities. Intervenors should recognize that intervention is not desirable in every case and that every decision to intervene or not to intervene should be conscious, explicit, and public. Intervenors must also honor standards of confidentiality agreed on by the parties and should recognize the uncertainty and limits of their influence. They must also be familiar with the dynamics of power and of the substantive issues in the situations in which they work. Twenty-one references are listed, and an illustration is included.