The purpose of this project was to evaluate the effect of the U.S. Army's education program on attitudes and knowledge about AIDS and behaviors related to risk of exposure to HIV. Subjects consisted of 503 male and female light infantry troops at Fort Ord, California. A questionnaire was designed to assess the subjects' level of knowledge, attitudes, and behaviors relevant to HIV infection at various points in the project. The following two approaches to HIV education were evaluated: the U.S. Army's standard AIDS briefing including a video and a brief didactic presentation, and a behaviorally-oriented HIV briefing consisting of a didactic presentation with subject participation and demonstrations. Prior to the briefings, the level of general knowledge about AIDS, including behaviors that convey the highest risk for HIV transmission, was very high. Despite this knowledge, subjects reported engaging in considerable high-risk sexual behavior. Those who reported behavioral intentions to practice safer sex or use condoms were not necessarily more knowledgeable about AIDS but reported other positive intentions consistent with their being change agents, including sharing information about risk-education with friends.