Restricted and repetitive behaviors are a core feature of autism spectrum disorder; however, research on the functional impact of these behaviors on the quality of life for individuals with autism spectrum disorder and their families remains scarce. We conducted focus groups with parents of children with autism spectrum disorder and clinicians in order to better characterize the functional impact of behavioral inflexibility, which represents one potential dimensional construct that could account for the breadth of behaviors comprising the restricted and repetitive behavior domain. Transcripts of the focus groups were analyzed using qualitative analysis coding methods to determine parent and clinician beliefs on a range of issues related to behavioral inflexibility including overall impact, types of child behaviors, and strategies for managing behavioral inflexibility. Thematic analysis revealed that parents and clinicians view behavioral inflexibility as an important behavior that impacts multiple areas of functioning, relates to other restricted and repetitive behaviors as well as social communication behaviors, and warrants targeted treatment. Notably, many parents and clinicians emphasized some positive consequences of behavioral inflexibility as well. These findings add crucial insights into the functional impact of behavioral inflexibility and restricted and repetitive behaviors as a whole and suggest that behavioral inflexibility represents an important avenue for future research.