Lean Practices have been implemented by private hospitals to get counterproductive solutions for reducing costs and gaining a competitive advantage. This research aims to examine the significance of lean practices on competitive advantage in the Sri Lankan private hospital sector to fill the knowledge gap. This research used a quantitative approach in which primary data was collected through a questionnaire-based survey and an analysis was conducted using structural equation modeling using the SmartPLS software. The research reveals the level of impact of lean practices, 5S, Kaizen, Kanban, and Just in Time in achieving a competitive advantage in the private hospital sector. Studies have demonstrated a significant impact of adopting the Just in Time approach in comparison to other established lean practices within the Sri Lankan private hospital sector, highlighting its unique and valuable contribution for health services. Researchers demonstrated when comparing Just in Time with other chosen lean practices for the study from the perspective of supply chain professionals, Just in Time contributes significantly to the competitive advantage of the Sri Lankan private hospital sector.