BACKGROUND AND AIMS: Patient-reported outcome measures (PROMs) for children (aged ≤ 18 years) present methodological challenges. PROMs can be categorised by their diverse underlying conceptual bases, including functional, disability and health (FDH) status; quality of life (QoL); and health-related quality of life (HRQoL). Some PROMs are designed to be accompanied by preference weights. PROMs should account for childhood developmental differences by incorporating age-appropriate health/QoL domains, guidance on respondent type(s) and design. This systematic review aims to identify generic multidimensional childhood PROMs and synthesise their characteristics by conceptual basis, target age, measurement considerations, and the preference-based value sets that accompany them. METHODS: The study protocol was registered in the Prospective Register of Systematic Reviews (CRD42021230833), and reporting followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We conducted systematic database searches for generic multidimensional childhood PROMs covering the period 2012-2020, which we combined with published PROMs identified by an earlier systematic review that covered the period 1992-2011. A second systematic database search identified preference-based value sets for generic multidimensional PROMs. The PROMs were categorised by conceptual basis (FDH status, QoL and HRQoL) and by target age (namely infants and pre-schoolers aged < 5 years, pre-adolescents aged 5-11, adolescents aged 12-18 and multi-age group coverage). Descriptive statistics assessed how PROM characteristics (domain coverage, respondent type and design) varied by conceptual basis and age categories. Involvement of children in PROM development and testing was assessed to understand content validity. Characteristics of value sets available for the childhood generic multidimensional PROMs were identified and compared. RESULTS: We identified 89 PROMs, including 110 versions: 52 FDH, 29 QoL, 12 HRQoL, nine QoL-FDH and eight HRQoL-FDH measures; 20 targeted infants and pre-schoolers, 29 pre-adolescents, 24 adolescents and 37 for multiple age groups. Domain coverage demonstrated development trajectories from observable FDH aspects in infancy through to personal independence and relationships during adolescence. PROMs targeting younger children relied more on informant report, were shorter and had fewer ordinal scale points. One-third of PROMs were developed following qualitative research or surveys with children or parents for concept elicitation. There were 21 preference-based value sets developed by 19 studies of ten generic multidimensional childhood PROMs: seven were based on adolescents' stated preferences, seven were from adults from the perspective of or on behalf of the child, and seven were from adults adopting an adult's perspective. Diverse preference elicitation methods were used to elicit values. Practices with respect to anchoring values on the utility scale also varied considerably. The range and distribution of values reflect these differences, resulting in value sets with notably different properties. CONCLUSION: Identification and categorisation of generic multidimensional childhood PROMs and value sets by this review can aid the development, selection and interpretation of appropriate measures for clinical and population research and cost-effectiveness-based decision-making.