A retrospective study was carried out from September 1996 to June 2000 and examined the antiretroviral therapies prescribed to HIV patients in whom the viral load had been determined. Triple therapy was the most frequently prescribed during the study and the annual percentage increased to 60% in the last semesters analyzed. Large variability in antiretroviral combinations was observed and depended on the clinical center and unit. The number of individuals who began viral-load monitoring before being treated with antiretroviral drugs showed a progressive increase.