The Pediatric Evaluation of Disability (PEDI) was developed as a comprehensive functional assessment instrument for pediatric rehabilitation. The PEDI samples content in the domains of self-care, mobility, toileting, and social cognition. These content domains are evaluated by three separate scales: 1) functional skills/behaviors, 2) caregiver assistance of complex activities, and 3) environmental modifications and equipment. The PEDI can be used as a parent report/structured interview instrument or by professionals observing the child's functional behavior in a hospital, outpatient, or educational setting. This article describes the development edition (pilot) of the PEDI and includes a report of a content validity study with 31 expert reviewers. Overall, the content validity and feasibility of the PEDI were supported. Revisions made in the standardization version of the PEDI based on the content validity study are discussed.