Autism spectrum disorder (ASD) is one of the fastest growing disabilities in the United States. As the number of children diagnosed with ASD rises there is a parallel increase in families and siblings of children with ASD (F-ASD). There is a gap in the research (Meadan, Halle, & Ebata, 2010) on the interaction between children with ASD and other family members, especially siblings. In this study I explored sibling relationships in families of children with ASD with a focus on children of elementary to early middle- school age. Three research questions guided the inquiry: 1) What is the nature of sibling interactions in families of children with ASD, and do the individual characteristics of the child with and without ASD influence sibling relationships? 2) How do family attitudes and beliefs about ASD have an influence on sibling relationships? and 3) What factors contribute to parental decisions to access sibling support services? Sibling relationships in families of children with ASD were examined through observations, interviews, and focus groups. Siblings with and without ASD, parents, and clinical professionals participated in the process in order to gain multiple perspectives. Consistent with qualitative methods (Miles & Huberman, 1994), a four-stage analytic process involving transcription of the data, coding and categorization, interpretation and identification of patterns and themes, and verification of the data was used to identify themes. Data analysis revealed one core theme and five subthemes. The findings of this study suggest that sibling relationships were bound by the way in which the ASD traits were seen in each child, the individual characteristics of each child, and the way in which the children and family perceived and understood their circumstances. The sibling relationships were, in many ways, similar to those between typical siblings but with an added layer of complexity related to the ASD. The findings are discussed with reference to current literature on sibling adjustment and relationships in families of children with disabilities. Implications for practice and future research are also discussed.