What is different about the conduct of evaluations in conflict zones compared to nonconflict zones--and how do these differences affect (if at all) the ethical calculations and behavior of evaluators? When are ethical issues too risky, or too uncertain, for evaluators to accept--or to continue--an evaluation? These are the core questions guiding this article. The first section considers how the particularities of conflict zones affect our ability to conduct evaluations. The second section undertakes a selective review of the literature to better understand how ethical issues have been addressed both in evaluation research and in evaluation manuals. The third section draws on a series of structured conversations with evaluators to probe more deeply into the ethical challenges they face in conflict zones--with a particular interest in the "ethical tipping points" of evaluators. The fourth section considers ways evaluation actors can manage ethical challenges in conflict zones, concluding with a brief discussion of how these issues might be located more centrally in evaluation research and practice.