HIV prevention education and counseling efforts have historically been directed toward those individuals considered at risk for exposure to HIV and assumed to be uninfected with HIV. In the late 1990s, prevention efforts began to include individuals who were HIV-infected. In 2003, the Centers for Disease Control and Prevention recommended that HIV prevention be incorporated into the medical care of persons living with HIV. This domain of HIV prevention work is known as prevention with positives or positive prevention, and research within this domain has been ongoing for a decade. This article provides a review of the scientific evidence within the prevention with positives domain from 1998 to 2008. A discussion is provided regarding early descriptive and formative studies as well as more recent and ongoing intervention trials specifically designed for persons living with HIV. A summary of current knowledge, a description of ongoing research, and gaps in knowledge are identified. Topics for future research are suggested.