The possibility that cultural factors such as ethnicity and religion can deter the spread of the HIV virus in the Third World is hotly debated. Using data on individuals ages 15 to 49 from the Guyana HIV/AIDS Indicator Survey (n=4,300), this study examines the relationship of these cultural factors, comprehensive knowledge of the disease, and behaviors reducing the risk of contagion. Statistical controls are included for gender, age, urban residence, marital status, education, and wealth. The study finds that ethnicity is the most consistent cultural factor, with East Indians being more likely to avert risk and Africans less likely. Religion is less consistent, though Muslims and Hindus engage in less risk than Africans, especially over the course of a lifetime. Having a comprehensive knowledge of the disease does not reduce risk.