Corruption is a major problem when governments regulate industries and procure goods and services. Most regulated industries make large, costly investments and sign long maintenance contracts. Many also deal with politically sensitive sectors subject to price controls and/ or creative tariff structures. Procurement contracts often have a large quality component that is difficult to measure and that can deteriorate under non- competitive bidding. Together, these factors create opportunities for large and costly forms of corruption. International organizations are increasingly recognizing corruption as a problem that undermines goals in infrastructure sectors. However, the role of these organizations is unclear. Most of the theoretical literature on anticorruption policy assumes a benevolent domestic government managing a corruptible agent. In such contexts, it is not immediately clear why international actors should get involved. What’s more if the domestic government is nonbenevolent, the government will resist the initiatives of international actors. This chapter is a first attempt to systematically characterize and describe the role of international actors in promoting anti- corruption policy in regulation and procurement. Drawing upon a variety of economic theories of corruption in these sectors, I analyze how international actors may play a role, develop specific policy applications, and consider empirical evidence. This chapter builds on the framework set out in Estache and Wren- Lewis (2011) that surveys economic theories of anti- corruption in regulation. That article considers how these theories have been applied and the evidence for- or-against the theoretical predictions. The chapter also draws on analyses of survey data on: anti- corruption policy in procurement by Piga (2011), privatization by Auriol and Straub (2011) and regulation by Boehm (2007). Each of these works focuses on anti- corruption policy implemented domestically, reflecting the lack of scholarship on the role of international actors in this area. My main contribution is, therefore, to consider theories of anti- corruption in light of the properties of international organizations. Thus, my objective is to systematically define ways that international organizations might be able to reduce corruption in regulation and procurement. I simultaneously highlight areas where international actors may in fact harm anti- corruption efforts. A deeper understanding of the negative consequences of international involvement in anti- corruption programs provides a useful framework for policy and highlights where further research might be useful. Section I begins by outlining the main economic theories of corruption in regulation and procurement. Three broad theoretical approaches are identified based on: (1) interest- groups, (2) information, and (3) cost- benefit analysis. Section II considers the role of international actors, with a special focus on what they can bring to the table: (1) greater resources and technology, (2) a different set of priorities, and (3) additional actors. The effect of each of these three properties on corruption is analyzed with respect to the three theoretical approaches. The chapter concludes with general lessons and the way forward.