Parents and professionals typically report problem behavior as a significant concern for children with fragile X syndrome. In the present study, the authors explored whether behaviorally based interventions would result in a reduction in problem behavior and an improvement in quality of life for 3 children with fragile X syndrome and their families. A multiple baseline design was used to demonstrate intervention effects for specific high-priority contexts (i.e., bedtime, running errands, and toileting). A multicomponent intervention plan was developed to teach the parents and child to effectively cope with the particular context. After intervention, there were substantial improvements in problem behavior and family quality of life within the given contexts. Results of this study demonstrated the effectiveness of behavioral intervention for children with fragile X syndrome.