This paper explores what it means to engage as an ethical researcher in the conduct of critical ethnography. During the years in which this critical ethnography of new language learners in a midwestern high school, the ethnographer actively participated in the life of the site. This paper poses the question of what such active involvement means for research ethics. Much of the literature on research ethics deals with Internal Review Boards standards, but this paper takes a reflective, ethnographic look at the researcher's own ethical practices in order to articulate and examine the underlying principles entailed in the decisions to intervene or not in the ongoing life of the site. (Contains 2 notes.)