Purpose: This study aims to provide normative values of a global activity performance questionnaire (ACTIVLIM-CP) and investigate its ability to discriminate children with cerebral palsy of various functional levels.Methods: Parents of 503 typically developing children aged 2-18 years old (mean age ± standard deviation (SD): 9.56 ± 4.62 years) and 285 children with cerebral palsy aged 2-18 years old (mean age ± SD: 10.08 ± 4.09 years) answered ACTIVLIM-CP. To provide normative values, influence of typically developing children's characteristics on ACTIVLIM-CP measures was investigated with a multiple linear regression. A Kruskal-Wallis test and Dunn's post-hoc tests were performed to investigate age differences in ACTIVLIM-CP measures. Discriminative ability of ACTIVLIM-CP was investigated using a one-way analysis of variance and post-hoc tests between children with cerebral palsy who differed in manual and gross motor functional levels.Results: In typically developing children, age was the strongest predictor, explaining 74% of the variance of ACTIVLIM-CP measures (β = 0.86, t = 38.21, p < 0.001). ACTIVLIM-CP measure increased with age until 17-18 years old where all children reached the maximal value, although 50% of the children at 12 years old already reached the maximal measure. Normative values were developed for each age bracket. In addition, ACTIVLIM-CP was able to discriminate children with CP's performance measures across most manual ability and gross motor functional levels.Conclusions: Normative values developed in this study with a representative sample of typically developing children allow clinicians to appraise the functional delay of children with cerebral palsy from the normal development of global activity performance. The good discriminative ability of ACTIVLIM-CP support its precision, construct validity, and clinical relevance to describe global activity limitations in children with cerebral palsy with manual ability levels and gross motor function levels II-V.Implications for rehabilitationNormative data of ACTIVLIM-CP developed with a representative sample of typically developing children can be used with children with CP to differentiate the age effect from the disruption caused by cerebral palsy.ACTIVLIM-CP showed the ability to discriminate across children with cerebral palsy having different manual and gross motor function, highlighting its precision, construct validity, and its clinical relevance to describe limitations in children with manual ability levels and gross motor function levels II-V.ACTIVLIM-CP covers a wide age range, is a cost-effective, easy and freely-available assessment of global activity performance in activities of daily living for clinicians.