The Group Guidance Project applied standard detached-work procedures to four large juvenile gang clusters containing approximately eight hundred youngsters over a four-year period. Project emphasis was on individual counseling and group pro graming. Research data revealed that the project was associated with a significant increase in gang delinquency, especially at the twelve- to fifteen-year age levels, and in high-companionship offenses. Analyses of inter-cluster differences and specific project events revealed positive relationships between levels of group programing, cohesiveness, and delinquency. The conclusion is that a group-work approach to gang intervention may inad vertently defeat its own purpose, at least in the absence of an active development of alternatives to gang participation.