Objective: A family cognitive-behavioral therapy for children and adolescents ages 8 to 18 years with clinical anxiety disorders was developed and evaluated. Method: Seventeen families were measured before and after waitlist, after treatment, and at 3-month and 1-year follow-up. Results: No children changed their diagnostic status during waitlist, whereas of the treated children, 41% were free of their primary anxiety disorder posttest, 57% at 3-month follow-up, and 71% at 1-year follow-up. Effect sizes of improvement were large for children's fears, dysfunctional beliefs, and interpretations of ambiguous situations and medium for children's internalizing and externalizing symptoms. Interestingly, fathers but not mothers reported less anxiety themselves after treatment. Large improvements were observed on parents' dysfunctional beliefs about their child's anxiety and their role as a parent. Finally, some improvements occurred in family and rearing variables. Conclusions: Family cognitive-behavioral therapy seems effective for clinically anxious children and their families. (Contains 4 tables.)