The recognition of anxiety as one of the most commonly co-occurring diagnoses for individuals on the autism spectrum has led to increased research on symptomatology and treatment, but there is limited research documenting the impact of this anxiety. To address this, this study reports on the Child Anxiety Life Interference Scale (CALIS, parent version) in a community sample of 121 parents of children on the autism spectrum. Scores indicate that the anxiety is impacting upon the child’s engagement in activities both in and outside of home as well as impacting upon parent life. Explanatory variables differed for CALIS subscales. As the child’s difficulties with uncertainty and parent level of anxiety were the variables that explained the most variance, these may be important foci for effective interventions.