Reviewing the strengths and weaknesses of the rating scales for anxiety disorders makes it possible to select appropriate measures for use in a multisite treatment study of children and adolescents with DSM-IV-diagnosed anxiety disorders. Categorical diagnosis for study inclusion is provided by the K-SADS-PL, which has strong published psychometrics for anxiety disorders. Broadband symptom ratings of diverse pediatric psychiatric disorder can be obtained at baseline by the parent-scored Child Behavior Checklist. Anxiety symptom monitoring may be provided by the use of two psychometrically strong self-report measures, the MASC and the SCARED. Weekly global ratings are provided by the CGI whose scale points have been enhanced by detailed anchors; in addition, the raters all trained on practice vignettes to calibrate their scoring. Clinician-based ratings of the patient's anxiety symptoms can be carried out in adolescent patients using the HAM-A. The newly developed Children's Anxiety Rating Scale promises to cover the full pediatric age range as a clinician-based anxiety rating instrument, but must first be subjected to formal psychometric and treatment sensitivity evaluation.