Developmental coordination disorder (DCD) is a neuro-developmental disorder characterized by poor fine and/or gross motor coordination. Children with DCD are hypothesized to be at increased risk for overweight and obesity from inactivity due to their motor coordination problems. Although previous studies have found evidence to support this hypothesis, their reliance on field-based measures, most notably body mass index (BMI), to determine body composition is problematic. Moreover, there has been no research to date that has examined whether THERE ARE differences in lean tissue mass between children with and without coordination. Differences in muscle mass, the main component of lean tissue, may be a contributing factor to both coordination problems and the development of overweight and obesity, but has only been indirectly examined at this time. In this study, whole-body air displacement using a dual chamber plethysmograph was used to estimate fat mass, fat free mass and body fat in children with probable DCD (pDCD) and a group of typically developing children. Consistent with previous research using field-based assessments of relative body weight, the results show that children with pDCD have much higher body fat than their peers, and that this difference increases with the severity of observed motor coordination difficulties. There was no difference in lean tissue mass between groups. The demonstration of an association between pDCD and body fat using a more sensitive measure of body composition, and evidence showing a dose-response in this relationship, further supports the hypothesis that DCD may be a risk factor for obesity in children. (Contains 2 tables.)