Children with developmental disabilities (DDs) have been observed to have delays in motor skills compared to their age-matched peers without disabilities. Empirical research suggests that children with motor skill delays experience more internalizing and externalizing behaviours and that early motor skill difficulties may be an important indicator of future increases in challenging behaviour. Yet, less is known about how this relationship exists in young children with DDs. The purpose of this study was to examine the association between motor skills and challenging behaviours in children with DDs at age five. It was hypothesized that children who have more proficient gross motor skills would have fewer challenging behaviours. Data for this project came from the Oregon Parenting Project. Participants (n= 95) included children with a DD at age five. Participants gross motor skills were measured using the Test of Gross Motor Development – second edition (TGMD-2) and behaviours were assessed with the of the Child Behavior Checklist for ages 1 1⁄2 - 5 (CBCL/11⁄2 - 5). Multiple linear regression analyses were conducted to determine the relationship between locomotor and object control skills on emotionally reactive, anxious/depressed, withdrawn, attention problems, and aggressive behaviours. It was found that object control skills were significantly related to withdrawn behaviour at age five in children with DDs. Locomotor skills were shown to be predictive of withdrawn behaviour, but not when child gender and parent education were included. Additionally, it was found that attention was significantly related to a child’s locomotor and object control skills when child gender and parent education were included. Future research should continue to investigate the relationship between gross motor skills and challenging behaviours in preschool aged children with DDs. Understanding this relationship will help parents and teachers utilize strategies and develop interventions to positively support kids with DDs at home, school and in the community.