During the last two decades, lean healthcare has received increasing attention from both researchers and practitioners because it plays an imperative role in quality and safety clinical process improvement. Although there is much evidence of the positive results of the paradigm implementation at the micro level, only in few cases the methodology is implemented at meso level or improvements are observed at organizational level. Among the main factors leading to the failure of meso implementation is the lack of widespread knowledge of lean tools and concepts within the organization. The lean implementation process at the meso level require high efforts to manage the transfer, sharing, integration, and transformation of lean knowledge within the organization. Thus, many researchers have positively assumed knowledge management (KM) as a critical success factor of lean sustainability and meso implementation. Although, the relationship of KM and lean sustainability have gradually become a hot topic, few scholars have investigated this issue in healthcare sector. Based on literature review focusing on the key characteristics of the lean healthcare implementation process, this article aims to bring out the relationships between lean tools, KM and lean sustainability in hospital setting. Results provide some relevant insights for hospitals applying the lean paradigm namely: KM is a critical success factor in disseminating and sustaining lean methodology and lean knowledge degree is strongly influenced by the use of lean tools.