The concept of Public-Private Partnerships (PPPs) and its application in procurement and development of infrastructure projects have been promoted worldwide due to the introduction of additional financing sources and value for money by this means. A large portion of debt or high leverage is usually structured in PPP infrastructure projects. It is very common for infrastructure PPP projects to undertake debt refinancing for improving project sponsors’ returns at a later stage. It is considered particularly suitable for long-term infrastructure projects where the construction has been completed and the successful operation has been demonstrated. The project profile has become less risky and can obtain better terms in refinancing. The aim of this research is to quantify the financing flexibility created by the future debt-refinancing opportunities and optimize refinancing plans in PPP infrastructure projects in the perspective of project sponsors. The scope of the research is to study the debt refinancing with the potential of return enhancement or generating refinancing gains in PPP infrastructure projects. This research contributes to the knowledge set on understanding the role of debt refinancing in PPP infrastructure projects by delivering the “option to refinance” valuation (ORV) framework and the debt-refinancing optimization (DRO) model.