To understand how lean thinking has been put into practice in healthcare and how it has worked. A realist literature review. Data sources The authors systematically searched for articles in PubMed, Web of Science and Business Source Premier (January 1998 to February 2008) and then added articles through a snowball approach. The authors included empirical studies of lean thinking applications in healthcare and excluded those articles that did not influence patient care, or reported hybrid approaches. The authors conducted a thematic analysis based on data collected using an original abstraction form. Based on this, they articulated interactions between context, lean interventions, mechanisms and outcomes. The authors reviewed 33 articles and found a wide range of lean applications. The articles describe initial implementation stages and emphasise technical aspects. All articles report positive results. The authors found common contextual aspects which interact with different components of the lean interventions and trigger four different change mechanisms: understand processes to generate shared understanding; organise and design for effectiveness and efficiency; improve error detection to increase awareness and process reliability; and collaborate to systematically solve problems to enhance continual improvement. Lean thinking has been applied successfully in a wide variety of healthcare settings. While lean theory emphasises a holistic view, most cases report narrower technical applications with limited organisational reach. To better realise the potential benefits, healthcare organisations need to directly involve senior management, work across functional divides, pursue value creation for patients and other customers, and nurture a long-term view of continual improvement.