The emerging sexuality that accompanies adolescence poses fundamental challenges for young people. These include adjusting to the altered appearance and functioning of a sexually maturing body, learning to deal with sexual desires, confronting sexual attitudes and values, experimenting with sexual behaviors, and integrating these feelings, attitudes, and experiences into a developing sense of self. The challenge is accentuated by the unfamiliar excitement of sexual arousal, the attention connected to being sexually attractive, and the new level of physical intimacy and psychological vulnerability created by sexual encounters. Adolescents’ responses to these challenges are profoundly influenced by the social and cultural context in which they live. In the United States, in contrast to many other Western nations, adolescent sexuality has typically been viewed as inappropriate and troublesome rather than as normal and healthy. In part, this reflects cultural mores about nonmarital sexual activity; in part it reflects well-justified concerns about potential negative consequences of sexual activity. Cultural proscriptions against nonmarital sex are counterbalanced by permissive attitudes reflected in the media and in the values of many adults. These competing perspectives co-mingle, creating a situation where adolescents are exposed to sexual material in settings of daily life but given inadequate preparation to behave responsibly in sexual situations. Feelings of sexual desire and love collide with social prescriptions to show restraint, setting the stage for psychological conflict and behavioral inconsistency. Despite a recognition of the subjective aspects of adolescent sexuality, the scientific literature has focused primarily on objective indicators such as having sex at certain ages, the behaviors adolescents practice, and the health-related outcomes of teen sexual activity (Moore & Rosenthal, 1993). While this approach helps define the scope of the “problem,” it fails to address the intrapsychic and interpersonal processes that influence whether intercourse occurs and whether protection is used. Understanding these subjective dimensions is key to developing effective interventions to reduce risky sexual behavior; it is also critical for grasping the meaning young people ascribe to their experiences, and the ways in which sexuality is integrated into their identities and intimate relationships (e.g., Brooks-Gunn & Paikoff , 1997). To provide an integrated picture of adolescent sexuality, we address three related issues: (1) recent trends in sexual behaviors among US adolescents; (2) individual and social factors influencing adolescent sexual behavior; and (3) how adolescents make sense of their sexual feelings and experiences. We highlight variations related to gender and ethnicity, but our scope is limited to heterosexual behavior. Wherever possible, we rely on recent national surveys for information on the attitudes and experiences of contemporary youth