The purpose of this investigation is to investigate a comprehensive, multi-component approach to the treatment of preschool children at-risk for Attention-Deficit/Hyperactivity Disorder (AD/HD) in home and school settings. The treatment program included schoolbased consultation, parent training, and if necessary, pharmacological treatment. A sample of 57 children identified as at-risk for AD/HD between three and five years of age were randomly assigned to an early intervention group (n = 30) or a community treatment control group (n = 27). Effect sizes were utilized to examine treatment outcomes. Results indicate mixed effects of early intervention on child behavior, parent-child interactions, family functioning, and pre-academic skills. Implications of these results for the implementation and further study of multi-component, early interventions for this population are discussed.