Children with Autism Spectrum Disorder (ASD) aged 11-13 (N = 16) and an IQ-matched typically developing (TD) group aged 7-12 (N = 16) completed a graded grammaticality judgment task, as well as a standardized test of cognitive function. In a departure from previous studies, the judgment task involved verb argument structure overgeneralization errors (e.g., *"Lisa fell the cup off the shelf") of the type sometimes observed amongst typically developing children, as well as grammatical control sentences with the same verbs (e.g., "The cup fell off the shelf"). The ASD group showed a smaller dispreference for ungrammatical sentences (relative to the control sentences) than did the TD group. These findings are indicative of a subtle grammatical impairment in even relatively high-functioning children with ASD.