A growing body of research shows that having an involved father enhances a child's well-being. This four-page issue brief, based on Mathematica's evaluation of the Early Head Start Fatherhood Demonstration, delineates lessons for policymakers and practitioners who are embarking on new efforts to increase fathers' involvement in Head Start and other programs and in their children's lives. Issues examined include designing, operating, and sustaining effective fatherhood initiatives. (Contains 1 figure.)