ABSTRACT Objective To know situations of vulnerabilities experienced by children and adolescents with cancer and their implications on health rights. Method A qualitative study, developed from 2017 to 2018, in two Santa Catarina hospitals. The interviewees were 11 family members of children/adolescents with cancer, a prevalent chronic disease identified in hospitalizations in 2017. A descriptive and thematic analysis was carried out based on the vulnerability and human rights framework. Results Among the chronic diseases, cancer was prevalent. Vulnerability situations were discussed considering the trajectories in the health care network, the challenges facing the care routine and the support networks for the exercise of the right to health. Final considerations Chronic diseases such as cancer require timely, decisive and effective responses from the health system with a view to maintaining human rights.