Ethnography is the defining practice – and art – of anthropology. Among health information technology (IT) developers, however, ethnography remains a little used and undervalued mode of inquiry and representation. In this chapter we demonstrate that ethnography can make important contributions to the design and implementation of more user-oriented health IT devices and systems. In particular, we propose ‘rapid ethnography’ as a pragmatic strategy that draws on classic ethnographic methods, but emphasizes shorter periods of fieldwork and quick turnaround of findings to inform (re)design, programming and implementation efforts. Rapid ethnography is theoretically and empirically situated in science and technology studies' explorations of a) the entanglement of social and technical dimensions of technology use; b) how getting tools to ‘work’ requires aligning interests across a wide range of human and non-human actors; and c) the ways in which humans and technology transform each other as they interact. We provide two detailed case studies to illustrate the evolution and uses of rapid ethnography at a U.S. academic medical center. By providing deeper insights into the experiences of users, and the contexts and communities in which new tools are introduced, rapid ethnography can serve as a valuable component of Techno-Anthropology and health IT innovation.