The association between HIV/AIDS knowledge, risk perception and risky sexual behavior remains a valuable area of study among scholars seeking to understand the AIDS epidemic in Africa. Past research has focused only on either the Health Belief Model or social epidemiology ideas to understand AIDS but never combined the two. The current study is unique and adds to the body of knowledge by making use of both the Health Belief Model and social epidemiology ideas to understand these relationships more clearly and, more importantly, to explore the role that keeping AIDS a secret has in the contexts of risk perception, knowledge and behavior. Data from the 2004 National Survey on Adolescents in Malawi were used to that end. The sample was comprised of 3,770 Malawian adolescents between the ages of 12 and 19. The hypotheses for this study were: (1) HIV knowledge has a direct effect on keeping AIDS a secret within the family; (2) there is relationship between keeping AIDS a secret and risk perception which is extra explained by HIV/AIDS knowledge; and, (3) keeping AIDS a secret within the family has an effect on sexual behavior which is mediated by risk perception and AIDS knowledge. The fourth hypothesis argued that these relationships differ by gender. Logistic regression models were fitted in separately for males and females to examine the direction of the relationship between keeping AIDS a secret within the family, AIDS knowledge, risk perception and risky sexual behavior. The findings indicated a strong association between AIDS knowledge and adolescents’ desire to keep AIDS a secret within the family. That is, the more factual a respondent’s knowledge base Page 3 iii was, the greater the inclination was to keep AIDS a secret confined to the family. This most likely is due to the strong stigma surrounding AIDS in Africa. The current study was unable to find a strong correlation between risk perception and risky sexual behavior. This was largely due to the fact that the data were cross-sectional. However, the research still found gender differences among male and female risk perception with more males perceiving their risk to be high. Such findings suggested a strong need for policy makers in Malawi to address the effects of gender roles on sexual activities among youths. Equally important would be increasing outreach efforts that work to reduce if not eradicate the stigma surrounding HIV/AIDS in Malawi.