This report was prepared for the UK’s Security Sector Development Advisory Team in June 2005. Its aim is to act as a basis for discussion and to provide an opportunity to learn from the successes and failures of intelligence and security legislation in various countries. Drawing on the body of academic work in this field and the knowledge of RAND staff, this report: provides a definition of intelligence; describes in detail how intelligence is produced; examines the role of intelligence in security sector reform; highlights the importance of control and accountability in intelligence structures; examines how six countries have developed and implemented intelligence legislation and associated reforms; and, finally, draws out a number of key lessons to be considered in any future security sector reform activity encompassing intelligence structures. The report outlines the choices that need to be made when designing or implementing legislative oversight on intelligence and security services. The report will be of interest to policy makers in countries seeking to reform their security sectors and to practitioners in the international aid community seeking to support security sector reform.