The anthropological theory of “ordinary ethics” makes the established case that ethics involves judgements made in specific situations and using criteria acquired through social interaction, but emphasises that ethics are usually relatively implicit, becoming explicit in response to crisis, controversy, and change. One of the questions raised by this theoretical perspective concerns the relationship of implicit ethical judgments to more explicit forms of ethics, such as an ethics code. To address this question, this study applies the theory of ordinary ethics to the ethics code of the American Anthropological Association (AAA), the largest professional association for anthropologists. This thesis also addresses two additional supporting research questions: First, how has the AAA ethics code changed over time, and why does it change? Second, what is the role and purpose of ethics codes in anthropology, and what are the limitations? A first, historical component of my research involved comparing different versions of the AAA ethics code, and seeing how these related to contemporary ethical debates and controversies. I then conducted qualitative interviews with eleven anthropologists. Participants described their experiences with and opinions of the AAA ethics code and the debates around it, their broader experience with and understanding of ethical issues and dilemmas in anthropological fieldwork, and their ideas about the usefulness and importance of codes of ethics to ethics education and decision-making in anthropology. The results of the ethnographic component of the research support the sense that anthropologists constitute a community, with members socialized in such a way that they share a highly explicit concern for the ethics of their own and their discipline’s practices. The historical research reveals that the code is revised in response to crises in the discipline. For some anthropologists, responding to crises by formulating shared ethical standards may strengthen a feeling of a community, but others who identify as anthropologists may feel excluded by the assumptions in those standards. The revision process inspires debate, and to that extent it serves as a way to have a shared conversation about ethics in the discipline. Anthropological fieldwork is already a case of ethics out of the ordinary, and the debates around the AAA ethics code are an extension of this.