Although relatively few teenagers have been diagnosed with AIDS and the extent of asymptomatic human immunodeficiency virus (HIV) infection among adolescents remains largely unknown, there is cause for concern about teens' risk of contracting HIV disease The incubation period (the time from initial infection to the development of full-blown AIDS) is estimated to average eight years, and therefore it is probable that most of the individuals in their twenties who have AIDS (20% of all the people with AIDS) contracted HIV during their teenage years. The sexual and drug use activities of many teenagers place them at increased risk for HIV transmission. Sexually transmitted diseases (STDs) are pervasive and a major cause of morbidity among sexually active adolescents. The rates of STDs have continued to rise even during the 'age of AIDS'. These rates are of concern since the behaviors associated with the acquisition and transmission of STDs are also the behaviors associated with HIV transmission. In addition, the presence of STDs may increase the likelihood of HIV transmission. Although condoms reduce the risk of HIV transmission, their use remains low among sexually active teenagers. Reducing or eliminating high risk behaviors is the only way to limit further spread of HIV. Effective prevention programs should be based on models and theories of risk behavior so that the programs can be designed to change those factors which lead to the undesirable risky behaviors. The AIDS Risk Reduction Model (ARRM) is presented as an example of such a social-physiological model. The ARRM model characterizes why people persist in engaging in high risk activities or make efforts to alter those activities. The three stages theorized to be necessary to reduce risky sexual activities are: (1) recognizing that one's activities make oneself vulnerable to contracting HIV; (2) making the decision to alter risky sexual behaviors and committing to that decision; (3) overcoming barriers to enacting the decision, including problems in sexual communication and seeking help when necessary to learn strategies to reduce risky behaviors. Each stage includes a number of constructs identified in prior research as important for engaging in 'healthy' or low risk behaviors. Innovative strategies must be developed and implemented to reach all adolescents, ranging from teenagers who attend school and live with their families to those teens who are runaways, live in detention facilities or are otherwise 'disenfranchised'. To be most effective, HIV prevention programs must utilize strategies which combine cognitive and behavioral skills training.(ABSTRACT TRUNCATED AT 400 WORDS)