This evaluation aims to inform the implementation of the most recent the World Bank and International Finance Corporation (IFC) health, nutrition, and population (HNP) strategies to enhance the effectiveness of future support. It covers the period since fiscal year 1997 and is based on desk reviews of the portfolio, background studies, and field visits. The evaluation of the HNP support of the World Bank focuses on the effectiveness of policy dialogue, analytic work, and lending at the country level, while that of IFC focuses on the performance of health investments and advisory services before and after its 2002 health strategy. The themes it covers are drawn from the two strategies and the approaches adopted by international donors in the past decade. Independent Evaluation Group (IEG) has previously evaluated several aspects of the Bank's HNP support. IFC's support for the health sector has never been fully evaluated. Many lessons have been learned over the past decade about the successes and pitfalls of support for health reform: First, the failure to assess fully the political economy of reform and to prepare a proactive plan to address it can considerably diminish prospects for success. Political risks, the interests of key stakeholders, and the risk of complexity- issues the evaluation case studies found to be critical are often neglected in risk analysis in project appraisal documents for health reform projects. Second, reforms based on careful prior analytic work hold a greater chance of success, but analytic work does not ensure success. Third, the sequencing of reforms can improve political feasibility, reduce complexity, ensure that adequate capacity is in place, and facilitate learning. When implementation is flagging, the Bank can help preserve reform momentum with complementary programmatic lending through the Ministry of Finance, as it did in Peru and the Kyrgyz Republic. Finally, monitoring and evaluation are critical in health reform projects-to demonstrate the impact of pilot reforms to garner political support, but also because many reforms cannot work without a well-functioning management information system.