Nearly 30 years ago, leading child psychologist Michael E. Lamb reminded us that fathers are the "forgotten contributors to child development." Since then, much work has been done to explore the ways fathers uniquely contribute to the healthy development of their children. Scholars now know that boys and girls who grow up with an involved father, as well as an involved mother, have stronger cognitive and motor skills, enjoy elevated levels of physical and mental health, become better problem-solvers, and are more confident, curious, and empathetic. They also show greater moral sensitivity and self-control. As they grow, well-fathered children are substantially less likely to be sexually involved at an early age, have babies out of wedlock, or be involved in criminal or violent behavior. They are much more likely to stay in school, do well there, and go to college. Fathers can help Head Start programs become more effective in achieving positive outcomes for children. Head Start programs can help to strengthen the parenting partnership, and help fathers to be more effective in their children's lives. These five "Building Blocks for Father Involvement" will support Head Start programs in their efforts to promote father involvement. "Building Block 1" provides up-to-date research on the essential role that fathers play in the healthy development of their children. It is important that Head Start staff and parents understand the importance of the parenting partnership and why fathers are essential to children's well-being. This knowledge will help them to better meet the needs of families and children. (Contains 11 resources and 46 endnotes.)