Alcohol consumption by individuals infected with HIV is an important medical management issue with significant implications for the effectiveness of antiretroviral therapy as well as an important evolving field of HIV research. Alcohol consumption is a risk factor for poor medication adherence and can modify liver drug metabolism, both of which can lead to the emergence of drug-resistant virus. Research indicates that alcohol consumption greater than 50 g/day (four or five drinks) is a risk factor for liver disease progression among patients with HIV/HCV coinfection. In addition, alcohol-induced cirrhosis can result in changes in drug metabolism in the liver through compromised liver function. More research studies are needed to elucidate the biological and molecular basis of the clinical changes induced by alcohol consumption in HIV-infected individuals and on the relationship of these changes to the effectiveness of HIV pharmacotherapy. Specifically, research areas that are of particular importance are (1) determining alcohol consumption levels and patterns and its impact on antiretroviral medication adherence, efficacy, and physician prescribing practices; (2) identifying behavioral interventions to enhance adherence to HIV medications and reduce alcohol consumption; (3) clarifying the relationships and interactions among alcohol metabolism, HIV drug metabolism, and pharmacogenetics; (4) elucidating the extent of liver toxicity due to antiretroviral therapy and drug-drug interactions in individuals who consume alcohol; and (5) delineating the contribution of alcohol consumption to end-stage organ damage, particularly in HIV/HCV coinfection.