Young people use augmentative and alternative communication (AAC) systems to meet their everyday communication needs. However, the successful integration of an AAC system into a child's life requires strong commitment and continuous support from parents and other family members. This article describes the development and evaluation of the Family Impact of Assistive Technology Scale for AAC Systems - a parent-report questionnaire intended to detect the impact of AAC systems on the lives of children with complex communication needs and their families. The study involved 179 parents and clinical experts to test the content and face validities of the questionnaire, demonstrate its internal reliability and stability over time, and estimate its convergent construct validity when compared to a standardized measure of family impact.