The aims of this study were to determine the quality of life of children with cancer and to compare their perceived quality of life with those of their caregivers. Purposive sampling was used to select 603 children diagnosed with cancer aged 6-18 years and their caregivers from eight hospitals in four regions of Thailand. Data were collected from the children and from their caregivers using self-completed questionnaires: 1) Demographic, 2) the Perception of Quality of Life of Cancer Children, and 3) the Perception of Caregivers Regarding Quality of Life of Cancer Children. The questionnaires were tested for content validity and for the reliability of questionnaires 2-3, yielding Cronbach’s alpha coefficients of 0.93 and 0.90, respectively. Results revealed that the overall level of perceived quality of life for both children and caregivers was high. The highest dimension score perceived by both children and caregivers was the life satisfaction dimension and that of the lowest was the psychological dimension. No significant difference of the overall mean scores in four regions of quality of life was found between children and their caregivers (t=1.53, p=0.13). There were significant differences of the overall mean scores of the quality of life perceived among children (F=16.38, p<0.001) and caregivers (F=10.87, p<0.001) in each region. Thus, nurses should consider the different perception of quality of life among cancer children or caregivers in each region and find how to enhance the quality of life especially a psychological dimension.