OBJECTIVE: Public-Private Partnerships (PPP) are a tool that the international development community, including international financial institutions (IFIs) are increasingly utilizing for developing and / or enhancing critical public infrastructure assets and services. The PNG LNG Project, ExxonMobil PNG Ltd used the PPP approach in multiple instances to support positive development outcomes. In the health sector, a PPP-known as the Partnership in Health Program (PiHP) -was developed to support Project, community and broader national health objectives. This PPP was not based on either physical infrastructure, (e.g., clinics, hospitals) or traditional clinical services, (e.g., out and inpatient care). Instead, ExxonMobil PNG Ltd developed the PiHP as an initiative focused on higher end scientific / medical services that would provide crucial data for overall countrywide public health policy development, planning and program implementation. The lessons learned from this five-year effort will be presented. METHODS:The long-term revenue stream of the PNG LNG Project is potential transformative for PNG's macro-economic position. PNG has an extremely high burden of disease largely dominated by infectious diseases. However, the pattern and distribution of disease is extremely uneven and some areas of the country are likely undergoing an epidemiological transition, i.e., a movement from infectious to non-communicable diseases. As part of the overall impact mitigation and extended benefits planning for the PNG LNG, a novel use of the PPP model was developed. Both impact mitigation and extended countrywide benefits for the health sector were incorporated into a PPP involving the statutory research arm of the PNG Ministry of Health [(PNG Institute of Medical Research (PNGIMR)] and ExxonMobil PNG Ltd. Formal ЉMemorandum of UnderstandingЉ and Sponsorship Agreements with key stakeholders were jointly developed. Scientific, financial and capacity development objectives were specified and included a set of key performance indicators. RESULTS:A five-year program was designed and implemented. Over 50,000 persons were covered and monitored by a comprehensive demographic surveillance system that was accepted into the 20 country international INDEPTH Network. This is the first PPP sponsored site accepted by INDEPTH in its 18-year history. A unique 2ϩ BSL infectious diseases research laboratory was developed under the PiHP and co-located within the PNG School of Medicine. Significant stewardship was provided and included financial accountability training and monitoring of PNGIMR. Important scientific discoveries involving tuberculosis, human papilloma virus, febrile surveillance and non-communicable diseases have been documented with significant public health policy implications. NOVEL / ADDITIONAL INFORMATION:The PPP model can be successfully adapted to meet both impact mitigation and extended benefit needs for a large oil and gas project. There are, significant Љlessons learnedЉ when undertaking a PPP of this size and magnitude. The ...