Background De-escalation is the recommended first-line response to potential violence and aggression in healthcare settings. Related scholarly activity has increased exponentially since the 1980s, but there is scant research about its efficacy and no guidance on what constitutes the gold standard for practice. Objectives To clarify the concept of de-escalation of violence and aggression as described within the healthcare literature. Design Concept analysis guided by Rodgers’ evolutionary approach. Data sources Multiple nursing and healthcare databases were searched using relevant terms. Review methods High quality and/or highly cited, or otherwise relevant published empirical or theoretical English language literature was included. Information about surrogate terms, antecedents, attributes, consequences, and the temporal, environmental, disciplinary, and theoretical contexts of use were extracted and synthesised. Information about the specific attributes of de-escalation were subject to thematic analysis. Proposed theories or models of de-escalation were assessed against quality criteria. Results N = 79 studies were included. Mental health settings were the most commonly reported environment in which de-escalation occurs, and nursing the disciplinary group most commonly discussed. Five theories of de-escalation were proposed; while each was adequate in some respects, all lacked empirical support. Based on our analysis the resulting theoretical definition of de-escalation in healthcare is “a collective term for a range of interwoven staff-delivered components comprising communication, self-regulation, assessment, actions, and safety maintenance which aims to extinguish or reduce patient aggression/agitation irrespective of its cause, and improve staff-patient relationships while eliminating or minimising coercion or restriction”. Conclusions While a number of theoretical models have been proposed, the lack of advances made in developing a robust evidence-base for the efficacy of de-escalation is striking and must, at least in part, be credited to the lack of a clear conceptualisation of the term. This concept analysis provides a framework for researchers to identify the theoretical model that they purport to use, the antecedents that their de-escalation intervention is targeting, its key attributes, and the key negative and positive consequences that are to be avoided or encouraged.