Earlier research suggests that diverse adolescent problem behaviors, such as substance use, school problems, early sexual intercourse, and delinquency, reflect a single underlying dimension of behavior. Data from an ongoing longitudinal study were used to examine this issue in a previously unexamined sample (N = 426) of preadolescent sixth-grade youth. Ss included boys and girls from diverse socioeconomic and racial/ethnic backgrounds, whose average ages were 11 and 12. By using confirmatory factor analyses to test competing models, multiple factor structures were detected, suggesting that earlier findings supporting a single factor conceptualization may not be generalizable to this age group. Implications of the finding that problem behaviors may be more differentiated in late childhood than in adolescence are discussed.