The Perceived Efficacy and Goal Setting System (PEGS) is an instrument and a process that enables children with disabilities to reflect on their ability to perform everyday occupations and to identify goals for occupational therapy intervention. In this study, 117 children with disabilities in grades 1–3 completed the PEGS with occupational therapists who work in school settings. Children from 6–9 years of age with a variety of disabilities were able to self-report perceptions of their effectiveness performing 24 activities that would be expected of them each day. Parents and teachers, who completed a parallel questionnaire, rated their abilities lower than the children did. The School Function Assessment, a measure of the amount and type of support required for school participation, had low correlations with the Parent and Teacher PEGS questionnaires and did not correlate with the Child PEGS. No differences in perceived efficacy were found for children across grades or gender; however, differences were found across types of disabilities. Children were able to use the perceived efficacy information to identify and prioritize goals for intervention and these goals remained stable 2 weeks later. Occupational therapists can use the PEGS within a client-centered practice to help the child set goals for therapy and to incorporate explicitly the perspectives of parents and teachers.