The aim of this lecture is to present on human immunodeficiency virus (HIV). HIV is thought to have entered into humans somewhere between 1914 and 1940. In 1983, a retrovirus, now called human immunodeficiency virus (HIV), had been identified as the cause of AIDS. The HIV antibody test has be used to screen all blood supplies in the U.S. since 1985. People receiving blood or blood products before 1985 may have been infected. Here also briefly present on Acquired Immune Deficiency Syndrome (AIDS).