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contraceptives. Demographic surveys of contraceptive use in the United States typically have collected and reported data only on use of single methods; when more than one method is described by a respondent, the one reported by the investigator is usually the method that most effectively prevents pregnancy.4 Likewise, studies of HIV and STD risk often do not include data on contraceptive use for pregnancy prevention. Of all age-groups, adolescents have the highest risk of infection with STDs5 and the largest share of unintended pregnancies in the United States.6 Several studies7 have demonstrated that, despite their increased risk of STD infection, adolescents who engage in sexual risk behaviors (e.g., those having multiple partners) are less likely to use condoms. Problem behavior theory8 postulates that adolescent risk behaviors (e.g., drug use, delinquency, early sexual involvement and having sex with multiple partners) often occur as part of a syndrome, with risk-taking in one area correlated with that in other areas. For example, adolescents who engage in early drug use appear to be more likely than those who do not to engage in early sexual behavior, and vice versa.9 This covariation presumably reflects underlying personality characteristics such as unconventionality,10 risk-taking11 or sensation-seeking.12 Early age at initiation of sexual intercourse may be a marker for adolescent psychosocial risk13 and has been associated with adult sexual risk behaviors and risk for STDs.14 An extension of problem John S. Santelli and Richard Lowry are medical epidemiologists, Charles W. Warren is assistant director for science, Ellen Sogolow is a research psychologist, Janet Collins is chief of the Surveillance and Evaluation Research Branch and Laura Kann is chief of the Surveillance Research Section, Division of Adolescent and School Health, Centers for Disease Control and Prevention (CDC), Atlanta, GA. Rachel B. Kaufmann is an epidemic intelligence service officer in the Division of Reproductive Health, CDC, and David D. Celentano is a professor in the Johns Hopkins University School of Hygiene, Baltimore, MD. The Use of Condoms with Other Contraceptive Methods Among Young Men and Women