Ancillary index scales provide assessment professionals the opportunity to conduct a more comprehensive interpretation of a student's performance on the Wechsler Intelligence Scales for Children, Fifth Edition (WISC-V); however, little is known about the performance of children with autism spectrum disorder (ASD) on these scales. The ASD special group population from the standardization sample of the WISC-V and their demographically matched controls were included in the study (total n = 124; mean age = 11.5 years). The results of a discriminant analysis revealed that the Auditory Working Memory Index, the Cognitive Proficiency Index, and the Full-Scale IQ were the best at discriminating among the different groups suggesting that the various groups perform differently on these indexes. School psychologists should calculate all ancillary index scales to obtain the most comprehensive understanding of the cognitive strengths and weaknesses of a child with ASD.