In order to develop suitable support for participation in pediatric rehabilitation, it is important to understand what barriers need to be bridged from the perspectives of both children and adults. The aim of this study was to explore barriers to participation in pediatric rehabilitation services, according to children and young people with disabilities, parents to children with disabilities, and professionals. Data was collected in individual interviews (n = 48) and focus groups (n = 8), which were analyzed with qualitative content analysis to extract barriers to participation. Identified barriers include three categories: (1) insufficient access (controlling adults, adult-centered healthcare); (2) insufficient trust (low level of trust in adults, low level of trust in children, low self-confidence in children); and (3) insufficient involvement (norms of non-participation, low level of commitment in children). The participant groups had divergent conceptions of where and how barriers originate, and for what situations child participation is appropriate. Adult-centered healthcare and parental presence were described as barriers by all participant groups. Understanding differences in the perceptions of barriers and their origins is crucial when striving to change norms of non-participation. The findings can inform the development of new support tools and participatory formats in pediatric rehabilitation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.