This study aimed to investigate the association between motor competency and social communication in children with Autism Spectrum Disorder (ASD) compared with children with Intellectual Disabilities (ID) and typically developing (TD) children. Motor competency, ASD symptoms, and nonverbal Intelligent Quotient (IQ) were investigated through the following tests: Movement Assessment Battery for Children, second edition (MABC-2), Social Communication Questionnaire (SCQ), Autism Classification System of Functioning: Social Communication (ACSF:SC) and Leiter International Performances Scale Revised (Leiter-R). The ASD+ID and ID groups had lower MABC-2-manual dexterity mean scores, MABC-2-aiming and catching mean scores, MABC-2-static and dynamic balance mean scores and MABC-2-TTS compared with the TD group (P<0.05). In addition, the ASD+ID group had lower MABC-2-aiming and catching mean scores compared with the ID group. In the ASD+ID group, we found a significant negative correlation (P<0.001) between MABC-2-aiming and catching scores with SCQ scores, nonverbal IQ and ACSF:SC levels. Our findings provide new insight into the common neuropsychological mechanisms underlying social communication and motor deficits in ASD. Multiple deficits in motor functioning may be present in ASD and ID, however deficits involving the ability to integrate motor and social cues are somewhat specific to ASD. Autism Res2018, 11: 893-902. (c) 2018 International Society for Autism Research, Wiley Periodicals, Inc. Lay SummaryThis study highlighted the specificity of motor impairment in ASD comparing performances on a frequently used measure of motor impairment between clinical groups (ASD+ID and ID) and a non-clinical group. While previous research has suggested that multiple deficits in motor functioning may be present in ASD, our findings suggest that deficits in tasks involving the ability to integrate visual and motor cues (aiming and catching task) are somewhat specific to ASD.