Understanding contextualized language use, how it mediates and is mediated by social practice has long been a central endeavor in English for Specific Purposes, with the aim of supporting the development of more tailored language instruction. This chapter examines how ethnographic approaches have become instrumental in this endeavor. It describes how the convergence of key conceptual developments in language and academic writing research have driven interest in ethnography, resulting in a common frame of practice which draws on values and methods shared across the social sciences. This framework has emerged from rigorous assessment by language and writing specialists of how ethnography’s theoretical underpinnings, core values, methods and ethical commitments can be adapted to meet the specific needs and concerns of language and academic writing research. After exploring the implications of this framework for ESP research, the chapter concludes with suggestions for areas of future ethnographic research in ESP.