This aim of this study was to validate the Scalpdex, a quality of life questionnaire for adults with scalp dermatitis, in children with scalp psoriasis. The reliability, responsiveness and validity of the 3 scales (symptoms, functioning and emotions) of this 22-item questionnaire were analysed in a cohort of children with scalp psoriasis (age range 6-18 years). A total of 94 children completed the questionnaire once, and 53 children a second time, after treatment of their scalp psoriasis. The Children's Scalpdex in Psoriasis (CSP) demonstrated reliability with internal consistency (Cronbach's α, 0.69-0.91). The CSP scales proved sensitive to change in the expected direction for children whose scalp psoriasis improved. Moderate effect sizes were observed between both visits for all 3 scales of the CSP (Cohen's d, 0.44-0.58). In conclusion, the CSP is a reliable, responsive and valid questionnaire, which is the first to illustrate the specific influence of scalp psoriasis on quality of life in children.