This chapter describes our efforts to develop what we call “bioethnography,” a research platform that combines ethnographic and biological data to arrive at better understandings of the histories and life circumstances that shape health and inequality. This platform is made possible through our collaboration with environmental health scientists involved in a longitudinal, pregnancy-birth-cohort and chemical exposure study in Mexico City. Bioethnography is a slow process due to the epistemic, temporal and logistical coordination of disparate and differently positioned intellectual research ecologies. To illuminate these efforts, we reflect on key issues and challenges that have arisen so far within three specific investigations within the larger collaboration (neighborhood dynamics, sleeping and eating), to provide a preliminary guide for social scientists contemplating similar bioethnographic projects. © The Editor(s) and The Author(s) 2018.