Over the course of the last decade, Stockholm has witnessed the emergence of a number of voluntary organizations that are active in the field of crime prevention. This article describes the "Lugna Gatan" project, which was initiated in Stockholm in 1994. The idea was to create an organization comprised of young adults aged between 20 and 30 whose objective was to get to grips with youth crime and vandalism on the Stockholm underground system. The young adults would patrol the underground system and attend public festivities directed at young people. Known as "stewards", those employed by the "Lugna Gatan" project would mediate conflicts between young people, intervene to prevent crime and initiate relations with youths at risk of becoming involved in crime or of becoming marginalized. In this way, the project was to overcome what was experienced as a growing social problem.