HIV is a virus that can lead to acquired immunodeficiency syndrome (AIDS), a disease that breaks down the immune system and allows for entry of life-threatening secondary infections. HIV is transmitted through the exchange of bodily fluids, primarily through sexual intercourse. South Africa has been one of the countries in which the AIDS pandemic has had an especially devastating effect. New cases of HIV infection in South Africa have been occurring at a high rate in people 15 to 24 years of age. There is no vaccine or cure for HIV yet, making disease prevention methods imperative. An important part of the prevention process is early education on HIV to reduce sexual-risk behavior and to promote safe sexual practices. This study will evaluate the effect of an HIV/STD risk-reduction program on the sexual behavior of South African adolescents.