The Joint United Nations Program on HIV/AIDS (UNAIDS) promotes the development of population estimates related to this epidemic, based on the use of the SPECTRUM software. In Chile, the estimates are updated annually, the last one corresponding to the year 2017, a process that included the participation of representatives of the Ministry of Health with the advice of experts from the UNAIDS headquarters in Geneva. The development of the 2017 estimation process yielded a number of 67,000 people living with HIV in 2017 (lower limit of 58,000 - upper limit of 76,000), with a prevalence in the group of 15 to 49 years of 0.6% (0.5-0.6%) and an incidence of 0,33 per thousand inhabitants. This document synthesizes the 2017 estimation process carried out in Chile, as well as the main results generated through this methodology.