The children's Yale-Brown obsessive-compulsive scale (CY-BOCS) is a commonly used, psychometrically sound clinician-rated instrument of pediatric obsessive-compulsive disorder (OCD) severity. Given the relatively direct rating format and potential benefits of alternative versions that could be easily administered to patients and parents, we developed and examined the psychometric properties of child- and parent-report formats of the CY-BOCS severity items. A total of 53 children and adolescents (8-17 years old) with OCD and their parents was administered the CY-BOCS, children's Yale-Brown obsessive-compulsive scale-child report (CY-BOCS-CR), children's Yale-Brown obsessive-compulsive scale-parent report (CY-BOCS-PR), and other measures of obsessive-compulsive symptoms, internalizing, and externalizing symptoms. In general, reliability and convergent and divergent validity of the CY-BOCS-CR/PR were satisfactory. Psychometric properties for the CY-BOCS-CR in those children and adolescents with externalizing behavior problems were lower relative to those without externalizing problems. Exploratory factor analyses identified a two-factor structure in both measures comprised of disturbance and severity factors. This study provides preliminary support for the use of child- and parent-report versions of the CY-BOCS.