In the era of highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV) infection has become a chronic disease in which patients may develop significant metabolic complications and risk factors for cardiovascular disease (CVD), including insulin resistance, visceral fat deposition, and increases in atherogenic cholesterol and triglyceride levels. Epidemiologic studies have found that persons infected with HIV are likely to be at higher risk for premature CVD compared with the general population, and clinical studies examining endothelial function in HIV-infected cohorts have supported such conclusions. The mechanisms underlying the regulation of endothelial function in HIV-infected persons appear to be multifactorial, including direct effects of HIV on the endothelium, indirect effects of HIV on lipids and inflammatory cytokines, HAART-related effects, and traditional/host factors. Better understanding of these processes can lead to improved strategies for the long-term management of HIV infection.