Research in child development suggests that parents' emotional competence and emotion socialization practices are related to children's emotional functioning, including child internalizing difficulties. This research has not yet been translated into intervention or prevention programs targeting parents of older children and adolescents. The current study examined the efficacy of the Tuning in to Teens parenting program in improving emotion socialization practices in parents of preadolescents and reducing youth internalizing difficulties. Schools were randomized into intervention and control conditions. Data were collected from 225 parents and 224 youth during the young person's final year of elementary school (sixth grade) and again 10 months later in their first year of secondary school (seventh grade). Multilevel analyses showed significant improvements in parental emotion socialization and reductions in youth internalizing difficulties for the intervention condition. This study provides support for the efficacy of the TINT parenting program with a community sample.