This study investigated the accuracy of brief anxiety scales for non-treatment-seeking youth with autism spectrum disorder. In all, 54 youth (7-17?years; IQ: 67-158) with autism spectrum disorder and their parents completed (a) an expanded version of the Anxiety Disorders Interview Schedule--Child/Parent designed to capture typical and atypical fears and (b) brief scales of anxiety symptoms (Behavior Assessment Schedule for Children, Second Edition; Screen for Child Anxiety and Related Emotional Disorders; Negative Affective Self-Statement Questionnaire; Pediatric Anxiety Rating Scale). The results indicate that measures lacked adequate sensitivity and specificity, and the detection of atypical fears was particularly poor. Revised cut scores are offered, but refined and/or revised instruments are likely needed for research on youth with autism spectrum disorder.