Elevated threat appraisal is a postulated neurodevelopmental mechanism of anxiety disorders. However, laboratory-assessed threat appraisals are task-specific and subject to measurement error. We utilized latent variable analysis to integrate youth's self-reported threat appraisals across different experimental tasks; we next examined associations with pediatric anxiety as well as behavioral and psychophysiological task indices. Ninety-two youth ages 8-17 years (M age=13.07, 65% female), including 51 with a primary anxiety disorder and 41 with no Axis I diagnosis, completed up to eight threat-exposure tasks. Anxiety symptoms were assessed using questionnaires and ecological momentary assessment. Appraisals both prior to and following threat exposures evidenced shared variance across tasks. Derived factor scores for threat appraisal were associated significantly with anxiety symptoms and variably with task indices; findings were comparable to task-specific measures and had several advantages. Results support an overarching construct of threat appraisal linked with pediatric anxiety, providing groundwork for more robust laboratory-based measurement.