Abstract: Japanese 5S was selected as the quality improvement tool in this study as 5S is the stepping stone for many quality improvement concepts and its roots date back to 16th century. When successfully implemented, 5S gives many benefits to the organization as well as its stakeholders. Though 5S itself has a tool to sustain, most of the organizations find it difficult to sustain the 5S practice over the time. Therefore the objective of this study was to find out the effect of the organizational leadership on the sustainability of quality improvement in Government Hospitals in Sri Lanka.