The oral manifestations of HIV infection present as a variety of opportunistic infections, neoplasms, and other lesions. Some of these are common, perhaps the most common, features of HIV disease and are highly predictive of the development of AIDS. Clinicians caring for HIV-infected persons should become familiar with the diagnosis and management of this group of conditions. The oral lesions of HIV infection present challenges of diagnosis and therapy. As the epidemic progresses, it can be expected that further lesions will be observed and that additional rational and effective therapeutic approaches will be developed.