This thesis employed a multi-sited ethnographic approach in urban and rural settings in Uganda to study the social and economic factors that shape antibiotic use. It found that these included everyday insecurities, availability of resources, and professional and patient expectations in health care settings. Surrounded by a pervasive rhetoric of ‘opportunity’ taking in these resource-scarce contexts, antibiotic use was framed as a way people could take advantage of the clinical research and humanitarian projects presenting medicines in their communities, with this ‘taking-of-opportunities’ becoming an end in itself. At the same time, ‘care’ in health facilities was characterized by delivery of medicines despite clinical guidelines specifying alternatives. Antibiotic use is central to the way people sustain everyday life in modern Uganda. This research provides insights that can inform locally relevant interventions seeking to optimize the use of antimicrobials and to curb AMR in Uganda and elsewhere.