Troublesome youth groups (TYGs) or "gangs" have been a research topic in the past, especially in the United States, and an increasing number of studies are currently being conducted in European countries. However, Belgium has been rather absent from the study of TYGs. This study aims to fill that gap in the literature. In the present contribution, the authors are interested in the prevalence of Belgian adolescents' involvement in TYGs and the role of societal vulnerability in this involvement. The authors are interested in the strength of the relationship between societal vulnerability and TYG and test the hypotheses that violent values and low self-control mediate the relationship between societal vulnerability and TYG. The analyses are conducted on the Belgian sample of the second edition of the International Self-Reported Delinquency study (ISRD-2). Both violent values and self-control mediate the effect of societal vulnerability and have strong independent effects on TYG. The implications of these findings are discussed. (Published Abstract)