This chapter presents the background, pathogenesis/etiology and epidemiology, and medical and dental management of acquired immune deficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV) and related conditions. HIV is the etiological agent for acquired immune deficiency syndrome AIDS. CD4+ lymphocyte depletion results in compromise of the host cell‐mediated immune response, placing the patient at increased risk for fungal, viral, and parasitic infections and some neoplasms. The physician should recommend dental consultation once HIV infection has been diagnosed. Physical examination is important in identifying and monitoring orofacial conditions that may be associated with HIV infection. Early HIV detection and access to HIV medical care and antiretroviral therapy (ART) can prolong the life span of the patient and also prevent future virus transmission. Unusual bacterial infections sometimes occur in the oral cavity of HIV‐infected patients. Treatment of these infections should be based on culture and sensitivity testing.