From 1984, when the first case of AIDS was diagnosed in Chile, to December 2003, 6.060 patients with AIDS and 6.514 with asymptomatic HIV infection have been notified to a passive national surveillance system; around 3,800 have died due to the infection. Magnitude of the under reporting is discussed. Assumed routes of the infection have been: sexual (94.1%), blood- largely intravenous drug use- (4.3%) and vertical transmission (1.6%). According to analysis performed by the National Commission on AIDS (CONASIDA), a governmental office, HIV/AIDS epidemic in Chile is characterized by: predominance in male homo/bisexuals, urban and rural distribution, impoverishment of the affected people, diagnosis made mainly during adulthood and a steady trend to affecting more women and heterosexuals at large. Since 2001 there has been a continuous increase in access to standard antiretroviral therapy (HAART) for those cared for by the public health system, reaching free coverage for 100% of this population by 2003, which has determined a significant decrease in the rate AIDS-associated clinical manifestations while reaching an stop of the previously increasing lethality of the infection (from a 15% increase from 1993-1997 to 0.2% from 1998-2003)