Background:In recent decades, the prevalence of chronic diseases in children and adolescents has increased significantly. Contextual factors play a central role in the self-regulation of chronic diseases. They influence illness and treatment representations, disease management, and health outcomes. While previous studies have investigated the influence of contextual factors on children's beliefs about their illness, little is known about subjective contextual factors of treatment representations of children and adolescents with chronic diseases, especially in the context of rehabilitation. Therefore, the aim of this qualitative analysis was to examine the contextual factors reported by chronically ill adolescents in relation to their treatment representations. Furthermore, we aimed to assign the identified themes to classifications of environmental and personal contextual factors in the context of the ICF.Methods:Between July and September 2018, semi-structured interviews were conducted with N=13 adolescent rehabilitants to explore their rehab-related treatment representations and associated contextual factors. The interviews started with an open narrative question about expectations and beliefs about rehabilitation, followed by further detailed questions. The interviews were recorded on audio tape, transcribed, and analysed using thematic content analysis. Results:Participants raised six themes associated with their rehab-related treatment representations that were interpreted as contextual factors: the living situation before rehabilitation, characterised by school and family problems, few social contacts, and intensive media consumption; the idea of rehabilitation, which mostly came from various people in the adolescent’s social environment; previous solution attempts; rehab pre-experiences; information that the adolescents received from the clinic or sought themselves; and the assumed attitudes of their parents concerning the presumed necessity of rehabilitation and expectations regarding the process and its outcome. All the themes could be assigned to the classification of environmental and personal factors in the context of the ICF for children and youth.Conclusions:Although contextual factors have an important impact on self-regulation, little attention is paid to their investigation. Personal and environmental factors probably influence patients’ treatment representations in terms of expectations and concerns as well as emotions regarding the treatment. Considering contextual factors could lead to the more appropriate allocation of medical care and the better customisation of treatment.