Fathers’ involvement in and influence on the health and development of their children have increased in a myriad of ways in the past 10 years and have been widely studied. The role of pediatricians in working with fathers has correspondingly increased in importance. This report reviews new studies of the epidemiology of father involvement, including nonresidential as well as residential fathers. The effects of father involvement on child outcomes are discussed within each phase of a child’s development. Particular emphasis is placed on (1) fathers’ involvement across childhood ages and (2) the influence of fathers’ physical and mental health on their children. Implications and advice for all child health providers to encourage and support father involvement are outlined.