The control of radioactive sources is a high visibility and high priority topic in contemporary society. Fatalities from orphan radioactive sources and the possible use of radioactive sources in radiological dispersal devices make it more important than ever that governments know about and have good control over radioactive sources within their territories, especially Category 1, 2 and 3 sources. This publication provides the necessary background and a systematic methodology for governments to evaluate how well they are controlling radioactive sources. Part I of the report provides details of the applications of radioactive sources and Part II describes the process for gathering information, performing an evaluation and then developing a prioritized national strategic action plan. Many examples of events involving sources are given as illustrations of the points discussed.