The 3-year program evaluation investigated the primary prevention aspects of Youth Assistance (YA), a community-based program of the Oakland County Probate Court providing casework and delinquency prevention services. Activities studied included parent education sessions, supervised teen recreation, summer camp scholarships, skill building activities, and a mentoring program. The goals of the study were to determine how effectively the program succeeded in mobilizing community volunteers, and to examine whether the incidence of neglect and delinquency had been reduced as a result of children and parents participating in one or more of these primary prevention activities. Highlights of the findings included: (1) YA primary prevention services resulted in improved communication skill, increased respect for authority, and more use of positive discipline techniques among at-risk populations; (2) 92 percent of program participants had no subsequent contact with YA or the Court; (3) the program is cost-effective; and (4) volunteers are an essential part of the success of a community-based prevention program. Tables, references