Objective: Identify the knowledge of family members of children and adolescents with cancer about their legal rights, difficulties, and concessions to ensure them. Methods: Quantitative study, survey type, of intersectional design. A questionnaire drawn up by the researchers was applied in order to characterize the minor and their family and also to identify the family's knowledge about legal rights. Descriptive statistics were used to analyze data. Results: 61 family members who participated know some more rights to the detriment of others and are especially motivated to search for information when negative impacts on the financial life increase, with repercussions beyond family health. Conclusion: the studied population requires more information and demands knowledge about some rights guaranteed by law. Guidance on rights empowers the family and guarantees the necessary care, searching to have an intersectoral action qualify care and assist in restructuring family dynamics to deal with chronic conditions.