The current study evaluates the psychometric properties of the Behavior Rating Inventory of Executive Function (BRIEF) with children with Down syndrome. Caregivers of 84 children with Down syndrome rated their child's behavior with the BRIEF. Teacher ratings were obtained for 57 children. About 40% of children with Down syndrome were reported by parents, and 70% by teachers, to exhibit clinically significant challenges with executive functioning. Distribution of scores was normal, internal consistency for subscales was questionable to primarily excellent, and inter-rater reliability was poor to good. Normative data conversions controlled for age, IQ, and gender differences, with some exceptions. The study findings suggest that the BRIEF and its subscales generally performed in a psychometrically sound manner among children with Down syndrome.