Although comprehensive and ecological approaches to early childhood prevention are commonly advocated, there are few examples of long-term follow-up of such programs. In this monograph, we investigate the medium- and longterm effects of an ecological, community-based prevention project for primary school children and families living in three economically disadvantaged neighborhoods in Ontario, Canada. The Better Beginnings, Better Futures (BBBF) project is one of the most ambitious Canadian research projects on the long-term impacts of early childhood prevention programming to date.