With its Lean production system, Toyota championed an innovative way to organize and manage processes to eliminate waste and improve effectiveness. While our understanding of Lean and its successes has grown, it has become increasingly clear that contextual variables impact the effectiveness of its implementation. In particular, there is a need to better understand those principles and practices of Lean that are most relevant for specific processes in knowledge work environments. In this paper, we use action research methods to explore the implementation of Lean techniques in the discharge planning process (DPP) of a large hospital. Our aim is two-fold: first, we conceptually frame and link our observations of Lean implementation in this knowledge worker setting with the overall framework of Lean management to provide researchers with further insight into important contextual elements/variables that need to be considered in this environment. Second, we articulate elements of Lean and its implementation that proved most useful and relevant in this environment. We identify critical elements of Lean that were central in this implementation and also identify key challenges of Lean implementation in this environment and link our findings to existing research on the topic