Background: Studies have shown that children and adolescents with autism and their relatives present a high level of stress and more family problems, impacting parents’ and caregivers’ quality of life (QoL). Despite studies on this subject, there is no specific questionnaire to evaluate QoL in parents or caregivers of children and adolescents with an autistic spectrum disorder (ASD) in Brazil. Therefore, this study’s primary purpose was to develop and validate a specific questionnaire to evaluate QoL in these individuals.