The Incredible Years (IY) Series is a well-established set of parent, teacher, and child programs for treating and preventing conduct problems and promoting social competence and emotional regulation in young children. The purpose of this article is to describe the development of this evidence-based series within the context of a prevention science framework. We first summarize the conceptual grounding of the intervention series including the risk and protective factors that are targeted by IY. We then review the extensive literature demonstrating the impact of the various programs. The bulk of this article, however, focuses on the challenge of disseminating evidence-based programs with high fidelity. To help overcome these challenges, we describe a model and a set of strategies for implementing IY in community and school settings with high fidelity, so as to help reduce the population prevalence of major childhood mental disorders. (Contains 1 figure.)