Anxiety and fear are among the most common and distressing problems reported by children and adolescents. However, these problems have received little attention from behavioural family theorists and therapists. In this paper, we argue that more attention needs to be paid to evaluating the role of family interaction processes in the development and treatment of child anxiety disorders. A program of research is described including a treatment outcome study in which family processes and behavioural family intervention are evaluated with 7- to 14-year-old children with overanxious, separation anxiety, and avoidant disorders. The family treatment focuses on how parents interact with their child during displays of anxiety, their management of emotional upsets, and family communication and problem-solving skills. Preliminary results of the family treatment are presented.