Evidence-based management (EBM) has been subject to a number of persuasive critiques in recent years. Concerns have been raised that: EBM over-privileges rationality as a basis for decision-making; 'scientific' evidence is insufficient and incomplete as a basis for management practice; understanding of how EBM actually plays out in practice is limited; and, although ideas were originally taken from evidence-based medicine, individual-situated expertise has been forgotten in the transfer. To address these concerns, the authors adopted an approach of 'opening up' the decision process, the decision-maker and the context (Langley et al. . 'Opening up decision making: the view from the black stool', Organization Science, 6, pp. 260-279). The empirical investigation focuses on an EBM decision process involving an operations management problem in a hospital emergency department in Australia. Based on interview and archival research, it describes how an EBM decision process was enacted by a physician manager. It identifies the role of 'fit' between the decision-maker and the organizational context in enabling an evidence-based process and develops insights for EBM theory and practice.