The impact of language delays and behavior problems in young children on family function was assessed using data from the 2003 National Survey of Children's Health. Over 50% of parents who reported concerns regarding their children's language skills also reported concerns regarding their children's behavior. Although parents reported increased stress and more difficulty coping and meeting their children's needs when they were concerned about their children's language skills, children with behavior problems were especially stressful for families. Parental stress increased as children with challenging behaviors reached preschool age. To address the negative impact on family function, service providers must couple specific intervention strategies and methods that improve language skills and mitigate behavior problems in young children. (Contains 3 tables.)