BACKGROUND: Financial toxicity is common among families of pediatric patients with cancer. However, the availability of survey and/or screening instruments specific to pediatric family financial toxicity is limited. METHODS: A two-round cross-sectional survey was conducted in Shandong Province, China. We combined classical test theory (CTT) and item response theory (IRT) to validate items of the caregiver-reported scale for pediatric cancer financial toxicity (CRS-PCFT) after Delphi. The scale structure, reliability, and validity were determined and validated by exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The threshold was discussed based on the correlations between CRS-PCFT and socio-factors. FINDINGS: A 16-item initial scale was determined after Delphi. The data from 206 pilot survey samples was used to select and validate items, and a 10-item CRS-PCFT was developed. The scale showed satisfactory reliability and validity based on data from 398 formal survey samples. When the CRS-PCFT scores were into high and low toxicity groups by the median, they were significantly correlated with education (r = -0.284, p <
0.0001), household income (r = -0.253, p <
0.0001), work status (r = -0.173, p = 0.001), and cancer stages (r = 0.147, p = 0.003). INTERPRETATION: CRS-PCFT demonstrates robust reliability and validity and makes it more accurate to obtain the pediatric cancer financial toxicity conditions. Additional research should be done to validate CRS-PCFT.