The topic of youth gangs has received considerable scholarly attention in the United States, and numerous publications have addressed the prevalence of, trends in, and responses to youth gangs. Relatively missing from this field, however, is examination of the youth gang phenomenon outside of the United States. In this volume, youth gang scholars from a variety of countries and disciplines provide unique insights into: 1) definitional and measurement issues; 2) group processes of gangs; and 3) gang research in a number of European countries. This key work is the fourth such product of the Eurogang Network, a cross-national collaboration of researchers, including top European and American scholars, devoted to comparative and multi-method research on youth gangs and troublesome youth groups. Some of authors are already well-known scholars in the field, while others are breaking new ground in terms of being the first in their countries to raise interest in and conduct research on youth gang issues. Authors come from a variety of scholarly disciplines as well as cultural perspectives, providing rich and diverse views of the youth gang phenomenon. The works presented in the chapters also represent various and rich research traditions, including ethnographic methods, self-report surveys or interviews of youth, surveys or interviews with law enforcement, official records data, and victim interviews. Importantly, and unique in this volume among the few texts that deal with gangs outside the United States all of the contributions utilize the Eurogang Program's definition of youth gang so that, while the groups they describe are located in different countries, comparisons may be drawn between them. The resulting work provides new insights into youth gangs outside the United States, and provides key questions for important future research.