The document brings in learnings based on review of IFC projects over a seven year period, consisting of more than 60 PPPs in over 35 developing countries, representing approximately $10 billion in investment, and delivering improved services to more than 30 million people. The defining feature of all these projects is a long-term partnership between the public and private sectors to deliver a public service, with some transfer of risk to the private partner. Ranging from hospitals in Africa to toll roads in South America to hydroelectric projects in Europe, and including both successful and failed projects, the case experience offers a rich and diverse array of lessons for anyone contemplating partnership between the public and private sectors. In fact, at the end of each project, IFC teams identified a handful of lessons learned, which was compiled into a database of over 350 lessons and then systematically analyzed. This report addresses the critical question: how can the public and private sectors build successful partnerships? Our research shows that the lessons fall into three broad categories: economics, politics, and execution. Indeed these categories represent the three fundamental forces that drive the success or failure of PPPs. Economics, politics, and execution are the spheres of activity that leaders must understand and manage if the projects are to be successful. Publication Date: 04.2013