We discuss the kinds and degrees of competence that the ethnographer needs to acquire. We consider the “unique adequacy” postulate, proposed by ethnomethodologists, that suggests that in the study of esoteric or specialized domains, the researcher needs to acquire or have previously acquired competence themselves. We suggest that this deserves more critical and nuanced scrutiny, not least given the impossibility of having prior competence in all aspects of a complex organization or activity. We also suggest that we need a more delicate appreciation of types of competence and, hence, of ethnographic knowledge. There is no single prescription, but a more thorough appreciation of the sociology of knowledge will inform ethnographic practice and methodological commentary.