Implementation of lean in manufacturing small and medium enterprises (SMEs) remains a serious challenge as many SMEs have failed at an early stage of lean deployment. Previous findings have concluded that manufacturing SMEs a lagging behind in terms implementing lean manufacturing and reaping its full benefits due to lack of effective lean pre-implementation framework to assess and SMEs readiness for change before deploying lean manufacturing. Similarly, there is a lack of lean manufacturing buy-in and low level of implementation among manufacturing SMEs remains in Nigeria. Coupled with the fact that research on lean manufacturing within SMEs is still a dearth in Nigeria and other developing countries at large. This study, therefore, proposes an effective framework for assessing lean readiness factors to organizational readiness for change with organisational culture as a mediator prior lean deployment among manufacturing SMEs in Nigeria. The aim of the study is to evaluate lean readiness factors that include; leadership, commitment, employee involvement, planning & control, process management, supplier relations and customer relations to organizational readiness to change to lean so as to evaluate whether manufacturing SMEs have the prerequisite quality practices, organizational culture and foundation needed to deploy lean. The study is based on a conceptual review of published literatures from various scholarly articles and reputable publications. The proposed lean readiness framework will serve as a comprehensive model for assessing manufacturing SMEs related quality practices prior lean deployment in order to be successful during full lean implementation. It will also be of great importance to both SMEs, researchers, governments and agencies towards promoting better quality practices in manufacturing SMEs.