The world is now facing the second decade of global epidemic of HIV infection. Most of the Asian countries including Singapore are seeing a trend of rapid increase of HIV infected cases each year. It is now known that the HIV disease has a prolonged asymptomatic period of several years before the onset of AIDS defining illness. A HIV-infected person may present to a physician at any point of the entire course of HIV infection. Hence, this article aims to give an overview of HIV disease and to provide information for doctors today to equip themselves with adequate knowledge to deal with this deadly infection.