Objective To develop the Cancer Symptom Help-Seeking Behavior Scale for Children with Leukemia (Parent Version), to test its reliability and validity, and to provide a scientific tool for evaluating help-seeking behavior in parents of children with leukemia regarding cancer symptoms.Methods Following COSMIN guidelines, and based on literature review and the cancer symptom help-seeking behavior conceptual model, interview outlines were developed for qualitative interviews.Based on the results of these interviews, an item pool was constructed.An initial version of the scale was formed through expert consultation.A pilot test was conducted with 30 parents of children with leukemia.Subsequently, 427 parents were surveyed, with data of 213 parents being used in exploratory factor analysis and 214 in confirmatory factor analysis to determine the scale′s reliability and validity.Results The final scale contained 16 items grouped into four dimensions:symptom observation, symptom cognition, help-seeking channels, and help-seeking actions.Exploratory factor analysis extracted four common factors with a cumulative variance contribution rate of 80.391%.Confirmatory factor analysis demonstrated good model fit (χ2/df=1.667,RMSEA=0.082,RMR=0.043,NFI=0.910,NNFI=0.952,GFI=0.910,CFI=0.961).The scale′s content validity index (S-CVI) was 0.867.The scale-level Cronbach′s alpha coefficient was 0.872, and the split-half reliability coefficient was 0.776.Conclusion The Cancer Symptom Help-Seeking Behavior Scale for Children with Leukemia (Parent Version) has good reliability and validity and can be used to assess help-seeking behavior related to cancer symptoms in parents of children with leukemia.