This study aims to determine the correlation between parents’ self-efficacy and the quality of life of children with cancer aged 8- 12 years. Quantitative research using a crosssectional design was carried out on 39 parents and 39 children with cancer. The participants were selected using a consecutive sampling method. The measurement instruments used were the Self-Efficacy for Parenting Task Index (SEPTI), the Pediatric Quality of Life InventoryTM (PedsQLTM) 4.0 Generic Core Scale, and the PedsQLTM 3.0 Cancer Module in the Indonesian version. Data analysis was performed using Pearson’s correlation coefficient. The results showed that parents’ self-efficacy and the quality of life of children were strongly correlated and that the direction of the correlation was positive (r= 0.680). Parents’ self-efficacy and quality of life children with cancer were also strongly correlated, and the direction of the correlation was positive (r = 0.715). It is recommended that parents and children with cancer ensure the adequate management of cancer treatment.