Although the rate of new cases of HIV infection has been relatively stable during the past decade, it remains unacceptably high, with 40,000 individuals newly infected each year. In 2001, the Centers for Disease Control and Prevention (CDC) issued revised guidelines for HIV counseling, testing, and referral directed toward promoting further reduction of HIV acquisition and transmission. The guidelines give explicit emphasis to the role of emergency physicians, according to recognition that the emergency department (ED) represents the only source of medical care for many patients and often serves as the primary site for routine health care to communities at risk for HIV. Despite the time and practical limitations inherent in ED practice, many studies suggest that routine HIV counseling, testing, and referral in the ED may be feasible and effective. This article reviews those studies in the context of the most up-to-date CDC HIV counseling, testing, and referral guidelines.