This article provides an overview of current research on Fragile X Syndrome, and how that knowledge can be used to guide successful intervention. The genetic etiology of Fragile X is reviewed and the physical, cognitive, adaptive, behavioral, and emotional phenotypes of children with the disorder are described, highlighting the differences in presentation among males and females. Comorbidity with autism is addressed. Typical strengths and weaknesses of children with Fragile X are delineated as a basis for educational assessment and intervention. A multidisciplinary approach to treatment is advocated, including medical management, educational accommodations, and speech-language and occupational therapy. The social and emotional challenges of those with the syndrome are considered in recommended interventions.