We report the results of a controlled prospective study designed to assess the impact of education on AIDS among elementary school students. 1,825 students from 3 school boards participated; 848 students were assigned to the trial group and 778 to the comparison group. Overall, the results showed a significant increase in students' level of knowledge of AIDS following their classroom lessons on AIDS. The students exposed to AIDS education expressed more accurate and appropriate beliefs about the transmission of AIDS. The students' reports indicated that television and magazines were their main outside sources of information about AIDS. Generally, the students demonstrated a positive attitude toward the AIDS curriculum. We conclude that classroom education on AIDS is effective in imparting knowledge and changing students' beliefs about AIDS. Further periodic assessments of AIDS education programs would be required at a variety of educational levels to determine if this change will lead to alteration in behaviour. Such assessments would help in the development of more comprehensive and cohesive programs in AIDS education.