The increasingly important topic of comparative criminal justice is examined from an original and insightful perspective by David Nelken, one of the top scholars in the field. The author looks at why we should study crime and criminal justice in a comparative and international context, and the difficulties we encounter when we do. Drawing on experience of teaching and research in a variety of countries, the author offers multiple illustrations of striking differences in the roles of criminal justice actors and ways of handling crime problems. The book includes in-depth discussions of such key issues as how we can learn from other jurisdictions, compare 'like with like', and balance explanation with understanding for example, in making sense of national differences in prison rates. Careful attention is given to the question of how far globalisation challenges traditional ways of comparing units. The book also offers a number of helpful tips on methodology, showing why method and substance cannot and should not be separated when it comes to understanding other people's systems of justice. Students and academics in criminology and criminal justice will find this book an invaluable resource.