• Sexually active adolescents should use condoms to prevent the transmission of sexually transmitted diseases, including human immunodeficiency virus. This study examined, among male and female adolescents, which beliefs about condoms are associated with intentions to use them if they have coitus in the next year. Teenagers attending adolescent health clinics completed self-administered surveys. Although most adolescents knew that condoms prevent sexually transmitted diseases, an increasing belief in the preventive effects of condoms was not associated with an increased motivation to use them. Instead, other immediate, short-term consequences, such as the ease with which they can be used and discomfort associated with their use, were most strongly associated with adolescents' intentions to use condoms. To encourage condom use, messages from physicians and other health care professionals must focus on adolescents' beliefs that are most likely to encourage or inhibit use of condoms. Health considerations should not be the sole emphasis of such communications if the goal is to increase the use of condoms among sexually active adolescents.