Two variants of a behavioral family intervention (BFI) program known as Triple P were compared using 87 preschoolers with co-occurring disruptive behavior and attentional/hyperactive difficulties. Families were randomly allocated to enhanced BFI (EBFI), standard BFI (SBFI), or a waitlist (WL) control group. At postintervention both BFI programs were associated with significantly lower levels of parent-reported child behavior problems, lower levels of dysfunctional parenting, and greater parental competence than the WL condition. The EBFI condition was also associated with significantly less observed child negative behavior in comparison to the WL. The gains achieved at postintervention were maintained at 1-year follow-up. Contrary to predictions, the enhanced program was not shown to be superior to the standard program using any of the outcome measures at either postintervention or follow-up. Each of the programs produced significant reductions in children's co-occurring disruptive behavior and attentional/hyperactive difficulties with 80% of the children showing clinically reliable improvement in observed negative behavior from preintervention to follow-up.