In this article, we examine the potential role that conspiracy beliefs regarding HIV/AIDS (e.g., “HIV is a manmade virus”) and birth control (e.g., “The government is trying to limit the Black population by encouraging the use of condoms”) play in the prevention of HIV, other STIs, and unintended pregnancies among African Americans in the United States. First, we review prior research indicating that substantial percentages of African Americans endorse conspiracy beliefs about HIV/AIDS and birth control. Next, we present a theoretical framework that suggests how conspiracy beliefs influence sexual behavior and attitudes. We then offer several recommendations for future research. Finally, we discuss the policy and programmatic implications of conspiracy beliefs for the prevention of HIV, other STIs, and unintended pregnancy.