The recently endorsed World Health Organization (WHO) International Classification of Functioning, Disability and Health (ICF) is proposed as a new tool to describe human functioning and health in a multiprofessional approach for individuals of all ages. Its application to paediatric neuro-rehabilitation may be of great help, especially in children with complex disabilities. However, experience with its application in this field is still limited. We tested the application of ICF in 40 children (26 males, 14 females; age range 3 to 18 years; mean age 11 years 1 month, SD 5 years 3 months) with various types and degrees of disability. We tested the applicability and reliability of the classification, and studied its correlation with well-established measures of functioning (Verbal IQ; gross motor function measure; functional independence measure). The ICF proved to be applicable and reliable, and strongly correlated with established scales. However, several of the Activity and Participation components do not fully capture the developmental nature of many abilities of children. Our study, although acknowledging the universal application of the ICF, and the ICF's value as a clinical tool, calls for its specific adaptation to accommodate better the peculiarities of child functioning and disability.