In the United States, Australia and Europe, many HIV infected individuals are still diagnosed and/or treated late in the course of the disease. This literature review of studies published over a ten year period between 1993 and 2003 has identified the following principle factors associated with the late diagnosis of HIV: male gender, aged older than 45 years, heterosexual intercourse, the lack of previous screening. It also identified the factors linked to the delay in beginning anti-retroviral treatment as being male gender, the lack of awareness or denial of the possibility of HIV infection, intravenous drug use, lack of post-screening follow-up or counseling, lack of social protection, and the lack of regular medical visits and care. Early detection and suitable early treatment of the HIV virus are the main determining factors which will effectively contribute to the control and maintenance of the virus in as much as they are focused upon these particular at-risk populations.