This article describes the development and validation of the Sport Anxiety Scale-2 (SAS-2), a multidimensional measure of cognitive and somatic trait anxiety in sport performance settings. Scale development was stimulated by findings that the 3-factor structure of the original Sport Anxiety Scale (SAS; Smith, Smoll, & Schutz, 1990) could not be reproduced in child samples and that several items on the scale produced conflicting factor loadings in adult samples. Alternative items having readability levels of grade 4 or below were therefore written to create a new version suitable for both children and adults. Exploratory and confirmatory factor analyses replicated the original SAS factor structure at all age levels, yielding separate 5-item subscales for Somatic Anxiety, Worry, and Concentration Disruption in samples as young as 9 to 10 years of age. The SAS-2 has stronger factorial validity than the original scale did, and construct validity research indicates that scores relate to other psychological measures as expected. The scale reliably predicts precompetition state anxiety scores and proved sensitive to anxiety-reduction interventions directed at youth sport coaches and parents.