The article discusses a research instrument developed and utilized by the Pittsburgh Girls Study that asked young girls (ages 7 and 8) and their caretakers to report on the girls’ involvement in a variety of problem behaviors. In this article, the authors evaluate whether comprehension, prevalence, and caretaker–child concordance of problem behaviors varied by child age and race. Results indicate that the girls understood most questions (except for some related to drug use) and that comprehension and reported involvement increased with age. Findings show that nonwhites showed greater comprehension and reported more involvement in problem behavior than Whites. Overall, the authors find modest concordance between reports from the girls and their caretakers, with greater agreement for nonwhites and older children. The authors conclude that a more comprehensive understanding of youth problem behavior is gained when both caretakers and children provide reports.