This study investigated the involvement of inner speech limitations in the executive dysfunction associated with autism spectrum disorders (ASDs). Seventeen children with ASD and 18 controls, statistically-matched in age and IQ, performed a computer-based card sorting test (CST) to assess cognitive flexibility under four conditions: baseline, with articulatory suppression, with a concurrent mouthing task, and while verbalizing their strategies aloud. Articulatory suppression adversely affected CST performance for the control group but not the ASD group. The results additionally showed that overtly verbalizing strategies did not benefit the ASD children as it did the typically developing children. The findings thus provide further evidence that ASD children do not use inner speech to the same extent, or with the same effectiveness, as typically developing children when performing executive tasks.