The Human Immunodeficiency Virus (HIV) is the causative agent for the expanding epidemic of the Acquired Immunodeficiency Syndrome (AIDS). Sixteen million individuals were estimated to be infected worldwide with HIV by the World Health Organization in 1995, with over 10 million in Africa and one million in the USA. As the HIV cost in dollars and lives continues to rise it will become more important to understand AIDS and to foresee the potential role of nuclear medicine in HIV diseases. Nuclear medicine may have a role in the assessment of immune function, including the ability to predict if individuals can avoid progression to HIV+status, if pre-AIDS to AIDS conversion can be prevented, and if an individual's immune status requires addition of prophylaxis. Also it can be used for disease detection at an early stage and determination of the extent of disease. It is especially useful to assist clinicians in optimizing therapy and assessing its efficacy. In the future new radiopharmaceuticals for detecting a specific infections and tumors will be needed. This will require collaborative efforts with basic scientists and clinicians working hand in hand to address specific issues related to AIDS.