This paper investigates factors associated with HIV prevalence among young people aged 15-19 years in Botswana. The paper utilises aggregated Botswana Aids Impact Survey I and II data sets to establish factors associated with HIV prevalence and whether there has been change in behaviours between the period 2001 and 2004. The paper used both the descriptive and multivariate analyses in establishing factors that could be responsible for the declining HIV prevalence among 15-19 year olds. There is ample evidence to show that between BAIS I and BAIS II, young people's knowledge on HIV/AIDS has improved. Secondly, there is evidence that some of their risky behaviours have positively changed such as decrease in multiple sexual partnerships and increased condom use. However, there are some negative developments that can be observed from the results of this paper. For instance, there is a significant increase in the number of youth who indulge in alcohol consumption. The results show that youth who are more likely to indulge in alcohol consumption are males, out of school youth, those with less education and disadvantaged youth. Another disturbing observation is that there is no significant decline in the number of young people who had sex before attaining age 16. In order to sustain the decline in HIV prevalence, it is evident from the findings that the youth in Botswana have to change certain behaviours. Female empowerment also appears to be an important area where policy and programme intervention is called for.