BACKGROUND Generalized Anxiety Disorder (GAD) in youth is characterized by excessive worry across domains for ≥ 6 months, an inability to stop worrying, and at least one physiological symptom. This study examined the multiple domains that optimally distinguish (1) GAD youth from nonanxiety-disordered youth and (2) GAD youth from other anxiety-disordered youth. METHODS Receiver operating characteristic analyses examined a sample of youth (N=180) aged 7-13 (M=10.10; 52% male), to determine optimal cut scores to distinguish GAD youth from (1) nonanxiety-disordered youth and (2) other anxiety-disordered youth. The diagnostic efficiency of worries and physiological symptoms was also examined. RESULTS By parent report, three worries and four physiological symptoms had favorable cut scores, and several specific worries possessed high diagnostic efficiency. Children endorsed fewer GAD symptoms. CONCLUSIONS Recommendations are made regarding the criteria for GAD in youth and interview sequencing of symptom queries.