Since 1984 to December 2004, 14.611 HIV/AIDS cases (85% in males) have been reported to the Chilean surveillance system. This figure represents an incidence of 103 x 10(5) inhabitants. The epidemic affects mainly men in their active working and sexual age. The main risk factor for infection, has been the sexual contact. Universal access to antiretroviral therapy (ART) has changed the epidemic trend. In 1997 bi-therapy and in 2003 three-drug therapy (HAART) were implemented. Mortality was 2,4 cases x 10(5) inhabitants during 2004, with a 67% reduction since 1984. Vertical transmission has been significantly reduced, as a result of implementing since 1995 a preventive strategy that benefits seropositive women and their newborn infant. Local experts are preparing an electronic registration system in order to optimize resources and to accede to statistics in a real time