Objective. Departing from the typical focus of intervention studies on service use and program effects for mothers and children, this article examines the extent to which fathers are present as clients in Early Head Start intervention programs for infants and toddlers. Design. The article uses descriptive findings from 2 studies: the first is a population survey of 261 Early Head Start programs (National Practitioners Survey), and the second is a father involvement demonstration program of 21 programs (Fatherhood Demonstration Study). Similar measures enabled comparability across the studies. Results. The 2 studies report that there was a father present in the lives of a majority of Early Head Start children - 70% in the national study, and 76% in the demonstration study. However, only 45% and 48%, respectively, of children had a father in residence, and there was considerable variation by race and ethnicity. About 59% of resident fathers had some participation in programs (53% in demonstration programs). Demonstration programs involved more nonresident fathers (45%) than did typical programs (30%). The proportion of resident fathers who were involved in Early Head Start at higher levels, defined in this study as at least 3 times a month, equaled 24% and 48% for typical and demonstration programs, respectively. For nonresident fathers, comparable figures were 10% and 30%. Conclusions. These studies illustrate that the majority of Early Head Start children have a father present in their lives, although many fathers are not in residence, and that the majority of fathers have some contact with the program. Findings showing that demonstration programs were more successful in engaging fathers at higher levels of involvement (especially true for nonresident fathers) illustrate that there is a greater potential for father participation in intervention programs than is realized today. Greater inclusion of fathers as clients in these programs has important implications for the science and practice of intervention.