Good public procurement practices are a major determinant of the effectiveness of public expenditure. Effective policies enable better use of government budgets and are therefore an essential element of the poverty reduction focus of the World Bank. More effective public procurement in countries may also allow procurement practices in the World Bank lending to be unified and harmonized with other donors. Two overarching questions form the core of this evaluation: To what extent has the World Bank helped countries develop better procurement capacity and improve their public procurement systems? And to what extent does the application of World Bank procurement policies in its investment lending help support its own development objectives? World Bank contributions to the procurement process in countries have taken the form of both advisory services and support through lending. IEG reviews the nature and quality of diagnostic work as well as loans focused on procurement reform — and the impact in terms of results. IEG’s findings lead to a number of recommendations that focus on developing plans and projects in the context of country strategies and implementing changes along prevailing best practices. The recommendations are specific to World Bank systems, although the challenges and issues of effective and transparent procurement are not. Lessons from this evaluation can be applied to improve procurement practices in any system.