The purpose of this study was twofold. First, the authors wanted to examine the associations of motor proficiency and body composition in children with and without dyslexia. They hypothesized there would be a negative relationship between body composition (measured by body mass index [BMI]) and motor proficiency (measured by MABC [Movement Assessment Battery for Children]), which would indicate that as BMI increased motor proficiency would decrease in both the typically developing and dyslexic groups. A second hypothesis was that children with dyslexia would show a stronger inverse relationship between BMI and motor proficiency than a typically developing population. The second purpose was to compare group differences statistically when children were grouped by either dyslexia or BMI status. They hypothesized that (a) children with dyslexia would have significantly higher BMI percentiles and lower MABC percentiles than their typically developing counterparts, and (b) when grouped by BMI, there would be significant differences in motor proficiency between the highest BMI group and all other groups. In this study, 49 children with and without dyslexia were measured on BMI and the MABC to examine the relationships between body composition and motor proficiency. Correlation analysis showed a significant, but weak, relationship between body composition and motor proficiency in the dyslexic group; no relationship existed in the typically developing group. These results partially upheld the first hypothesis. However, the hypothesis that typically developing and dyslexic groups could be differentiated on the basis of MABC or BMI was not upheld. When the groups were combined and divided into three specific subgroups within smaller BMI ranges (regardless of disability status) and compared on MABC percentiles, significant differences existed between children with the highest and lowest BMIs. Further, there was a trend toward differences between groups including the highest and medium BMI percentiles. This provided partial support for the final hypothesis. (Contains 1 table and 1 figure.)