This article includes the oral manifestations which have been reported to be associated with human immunodeficiency virus (HIV) infection. The clinical appearance, diagnostic criteria and treatment of fungal, viral and bacterial infections, neoplasms and lesions of uncertain etiology are described. Accurate diagnosis of the oral lesions is important in the management of patients infected with HIV. Identification of oral lesions may suggest the need for HIV testing or may be an indicator for preventive intervention. Early identification, diagnosis and treatment may prevent extensive tissue destruction and may improve the quality of life for HIV-infected patients.