Motor skill and postural stability deficits are commonly reported for children with autism spectrum disorder (ASD), however the relationship between these variables is not well established. We explored the relationship between motor skills, postural stability, restricted and repetitive patterns of behavior, diagnosis, age, and sex. Children (11 with and 11 without ASD), 5-12 years of age, participated in the study. The Test of Gross Motor Development-3 (TGMD-3) was used to assess fundamental motor skills. Postural sway was measured on a force plate during quiet standing on a solid and compliant surface. Center of pressure was calculated and used to compute sway area. Linear regression analysis showed that sway area on a solid surface, age, and diagnosis were significant predictors of motor skill performance (R-2 = .854). Severity of ASD, as assessed by the Repetitive Behavior Scale Revised (RBS-R), was not predictive of motor skills. Children with ASD exhibited deficits in postural stability compared to children without ASD. Postural stability appears to influence the ability of children to perform gross motor skills. However, the RBS-R does not seem to be a useful tool for identifying those children with ASD who exhibit the greatest deficits in motor skills. (C) 2016 Elsevier Ltd. All rights reserved.