In the context of the development of the International Classification of Functioning, Disability and Health Core Sets for children and youth with cerebral palsy, an evidence-based methodology was implemented to select the most relevant categories out of the entire classification. The aim of this study was to describe the contribution of the clinical perspective to select categories of functioning in children and youth with cerebral palsy. We conducted a chart review of clinical assessments of children and youth with cerebral palsy aged 0 to 18 years in a tertiary level center. In total, 129 International Classification of Functioning categories were covered in clinical encounters: representing 19% body structures, 33% body functions, 37% activity and participation, and 11% environmental factors. Our findings can guide clinical assessments and goal-setting of this population. This important perspective will inform the development of the International Classification of Functioning, Disability and Health Core Sets for children and youth with cerebral palsy.