There were 36.9 million in the world living with human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS) as of 2017, and new infections have seen a reduction by 18% since 2010. But this rate of decline is not sufficient for the goal of eradication of AIDS by 2030. Only 21.7  million people infected with HIV have accesses to antiretroviral therapy, with the rest at risk of the potential complications of HIV infection. It has been shown that oral lesions are diagnostic and prognostic of HIV infection, and many oral opportunistic infections continue to be a major problem, particularly in developing countries. It is therefore important that dental surgeons be aware and updated to recognize and manage the oral effects of HIV infection/AIDS. This chapter describes the classification, diagnosis, and management of oral lesions in these patients, based on our current understanding of the infection. This review also discusses the standardization of diagnosis of oral lesions in HIV infection/AIDS patients, immune reconstitution inflammatory syndrome case definition, and the research priorities formulated at the 7th World Workshop on Oral Health and Disease in AIDS.