Purpose The purpose of this paper is to develop a framework to assess the lean readiness within emergency departments (EDs) and identify the key quality practices deemed essential for lean system (LS) implementation. Design/methodology/approach An extensive review of the lean healthcare literature was conducted, including LS implementation within the healthcare sector (both generally and in EDs), best ED quality practices, essential factors for LS implementation within healthcare and lean readiness assessment frameworks. The authors identified six main categories from a literature review (top management and leadership, human resources, patient relations, supplier relations, processes and continuous improvement (CI)), and validated these based on experts' opinion. Findings Several factors were identified as crucial for EDs, including top management and leadership, human resources, patient relations, supplier relations, processes and CI. Originality/value To the author's knowledge, this is the first lean readiness assessment framework for EDs and one of the few lean readiness assessment frameworks in the literature.