This essay explores the contributions of "Evaluation Practice" and the "American Journal of Evaluation" to our understanding of evaluation ethics. The review is organized according to the five Guiding Principles for Evaluators (Systematic Inquiry, Competence, Integrity/Honesty, Respect for People, and Responsibilities for General and Public Welfare) and identifies key themes within each domain. The value of case-based ethical analysis is highlighted, as is the need for increased empirical research on ethical dimensions of evaluation, especially as these dimensions are perceived by stakeholders with whom evaluators interact. Over the past 25 years, evaluators have learned a great deal about the ethical challenges they are likely to encounter during any given stage of an evaluation, even as they continue to engage in debate over the roles through which evaluators can best serve the public interest. (Contains 1 note.)