A multitude of oral lesions, including unique forms of periodontal disease, have been discovered in individuals infected with the human immunodeficiency virus (HIV). Although the frequency of HIV-associated periodontal diseases appears to be less than previously thought, many researchers agree that an important factor influencing the prevalence of unique periodontal disease in the HIV population is the degree of immunodeficiency. The pathogenesis of HIV-associated periodontal diseases remains unclear, but may be the result of microbiota and/or alterations in the host. HIV-gingivitis, now called linear gingival erythema, and HIV-periodontitis, now called necrotizing ulcerative periodontitis, have microbiology profiles similar to conventional adult periodontitis, although these lesions are quite different clinically. This article reviews clinical signs and symptoms, treatments, and the pathogenesis of HIV-related periodontal findings. It specifically focuses on the immuno-incompetence of HIV disease as a risk factor for periodontal disease. Because the caseload of acquired immunodeficiency syndrome patients will increase significantly in the future, the dental practitioner must be able to recognize and manage the periodontal lesions associated with HIV infection.