OBJECTIVES:  The Brazilian STD/AIDS Programme stands out for ensuring universal and free access to antiretroviral drugs. We estimated the Federal expenditure on antiretroviral drugs of the Brazilian STD/AIDS Programme, during the period 2004-2008, and compared it to epidemic indicators of the Brazilian population. METHODS:  The expenditure on antiretroviral drugs comes from a data warehouse of the Ministry of Planning, Budget and Management that stores the information concerning any purchase made by the Brazilian Federal Government. The epidemiological indicators of AIDS are derived from the Brazilian STD/AIDS Programme, which combines data from different national information systems. RESULTS:  The expenditure on antiretroviral drugs rose from US$144.416.113,57 in 2004, to US$333.050.295,64, in 2008. In Brazil, from January 2004 to June 2008, there were 148.852 cases of AIDS reported, which corresponds to an incidence rate of approximately 20 cases per 100 thousand inhabitants. In the period from 2004 to 2007 there were 44.381 deaths due to AIDS in Brazil, representing a crude mortality ratio of about 6 deaths per 100 thousand inhabitants. CONCLUSIONS:  The use of antiretroviral drugs increases the survival of patients with HIV/AIDS and reduces the mortality rate. Despite the stability of AIDS incidence and mortality coefficients over the analyzed period, the expenditure increased, which can be due to an increase in coverage and range of drugs offered. As the resources are limited, it is important to understand the magnitude of the consumption as well as the mechanisms of purchase in order to improve the supply of antiretroviral drugs.