This article aims to investigate changes in primary school students' reported exposure to AIDS information and communication, and knowledge levels from 1992 to 2005. A repeated cross-sectional design was used. In 1992, a self-administered questionnaire was completed by 2,026 sixth and seventh grade students from 18 randomly selected primary schools in Arusha and Kilimanjaro regions, Tanzania. The same procedures were repeated in 2005 with a sample of 2,069 students. Mean values with 95% confidence intervals are reported. Chi-square was used to test for differences in proportions. Students in 2005 reported higher levels of exposure to information and communication from all sources than in 1992. Knowledge scores also increased, yet there was a significant decline in four variables, two of which are related to transmission and two of which are factual. An alarming decline in awareness of the condom as a preventative measure was found. Findings also indicate that myths related to transmission and infection persist. Salient sex differences remain, but the knowledge gap is narrowing. Interventions should aim to stimulate discussion in young people's social networks in order to increase overall exposure to AIDS information, communication and knowledge.