The Boys' Club Study, using descriptive, ecological, statistical, and case-study methods, showed that this particular club during its first four years was not an important factor in delinquency prevention. Although it did not reach a large number of the boys it was designed to serve, it did succeed in enrolling a more "underprivileged" class of boys, probably including more potential delinquents than among the non-members of the same age groups. As might be expected because of the types of boys enrolled, the Boys' Club delinquency rates were higher than those of the community in general. The increasing delinquency rate among club members, however, appeared to be the result of increasing age rather than the effect of participation in the club activities. The Boys' Club has an essential function to perform as a unit in a concerted community program designed to achieve crime prevention rather than as a single preventive agency.