Although anxiety is frequently reported in children with autism spectrum disorder (ASD), existing anxiety scales are often psychometrically inappropriate for this population. This study examined the internal structure, reliability, convergent and discriminant validity of the Spence Children's Anxiety Scale-Parent Report (SCAS-P; Spence 1999) in 238 school-aged children with ASD. While confirmatory factor analysis did not support the original six-correlated-factor structure, structural support as well as acceptable internal consistency and convergent validity was found for Generalized Anxiety, Separation Anxiety, Panic, and Agoraphobia subscales. Use of the SCAS-P in its original form for assessment in children with ASD was not supported. However, four subscales showed viability, and may benefit re-analyses of existing SCAS-P data and future scale adaptations for research and clinical purposes.