Using the 2003 National Survey of Children's Health, this paper examines the physical and mental health of children by family structure. Children in step, single-mother, or grandparent-only families had poorer health than children living with two biological parents. Adjusting for demographic differences reduced observed disparities, although children living in single-mother or grandpa rent-only families still had poorer health than children living with two biological parents. Adjusted estimates showed that children in single-father families generally did as well as (for mental health) or better than (for physical health) children living with two biological parents.