Overall, results indicated that active parent participation in their teenager’s treatment for substance abuse and severe behavioral problems had a significantly positive impact on treatment program effectiveness. Specifically, findings revealed a significant drop in teenagers’ self-reported substance use, although teenagers’ attitudes and defensiveness toward drugs and alcohol did not significantly change. The findings suggest that a group-oriented, family therapy psychoeducational approach can be effective in helping parents reassert their authority and reduce teenager’s severe behavioral problems and substance abuse. Participants were 102 adolescents and 93 parents who together attended a 6-week substance abuse prevention program called Parenting with Love and Limits. The Adolescent SASSI questionnaire was completed by the adolescents prior to beginning the program and recidivism and relapse information was gathered from juvenile court records at 6- and 12-months following program completion. Data analysis techniques included t-test calculations. Future research should focus on discovering which particular concepts or techniques within the Parenting with Love and Limits program is reducing parental resistance and increasing their readiness for change. Table, references