AimTo assess the impact of childhood cancer and its harmful effects on health-related quality of life (HRQoL) in children and adolescents based on both the mother's perception and the child's self-perception.Subject and methodsThe Pediatric Quality of Life Inventory (PedsQL & TRADE;) 3.0 Cancer Module was administered to 52 pairs of mothers and children/adolescents aged 1-18 years. The participants were recruited from a pediatric hematology/oncology center in a Brazilian public hospital. Data analysis included descriptive statistics and logistic regression.ResultsThe majority of the total sample were male (57.7%), aged 1-8 years (59.6%), and the main diagnosis was leukemia (88.5%). The family income was less than twice the monthly minimum wage in 90.4%, and 76.9% of the mothers had more than 8 years of education. In both groups, the descriptive analysis revealed lower scores in the Procedural Anxiety, Nausea, and Concern domains of the PedsQL & TRADE; 3.0 Cancer Module. There were no associations between the variables according to the mothers' perceptions. On the other hand, in the self-reports of children/adolescents, associations were found between HRQoL scores and the age group 9-18 years (OR = 5.74; 95% CI: 1.16-28.49), diagnosis of lymphoma (OR = 16.98; 95% CI: 1.33-216.29), and mothers with less than 8 years of education (OR = 6.71; 95% CI: 1.28-35.07).ConclusionThe age of the child/adolescent, type of cancer, and the mother's schooling were factors that exerted a negative influence on the self-perception of HRQoL among children/adolescents in treatment for cancer. The same was not found when the mothers were asked about the HRQoL of their children. With these findings, implementation in public health can be adopted based on actions and interventions in treatment, seeking a better HRQoL or even its restoration.