The current study evaluated the feasibility and validity of a parent-report measure of separation anxiety, the Separation Anxiety Daily Diary (SADD). Mother and child participants consisted of three groups: 96 children (aged 4-15 years) with separation anxiety disorder, 49 children with "other" anxiety disorders, and 43 healthy controls. The SADD assesses the frequency of anxiety-provoking and non-anxiety-provoking separations, along with associated parental anxiety, thoughts, child behaviors, and corresponding parental reactions. The SADD demonstrated acceptable compliance and convergent validity with hypothesized measures. Substantial improvement in the prediction of diagnostic group membership was shown when SADD items assessing child symptoms were added to information gathered from a separation anxiety symptom questionnaire. (Contains 5 tables and 3 footnotes.)