This book discusses the issues related to transparency, accountability and effectiveness in a number of international financial institutions and makes an assessment of the first ten years of activities of the Independent Investigation Mechanism (IIM) at the Inter American Development Bank (IDB). The first part consists of general and introductory material. The concepts of transparency, accountability and effectiveness as well as existing accountability mechanisms at some of the international organizations are presented and the main characteristics of the Independent Investigation Mechanism of the Inter American Development Bank are presented. The second part introduces a set of case studies. Cases submitted to the IIM, from its creation in 1994 until December 2005, and their outcomes are discussed. Each case is presented in a separate chapter and lessons are drawn for future use. This book will serve the purpose of illustrating the complexity of monitoring development projects and the various internal and external problems associated with them. In addition, it emphasises the need for carefully established investigation structures as tools to increase transparency, cater for accountability and ensure efficiency in the use of financial, human and natural resources.