Objective: To assess the behavior of Beta-2 microglobulin and serum cytokines TNF-α, IFN-γ, IL-2, IL-4 and IL-10 as indicators of highly active antiretroviral therapy (HAART) failure Design: Cross-sectional study. Methods: Eighty-nine HIV-1+ patients and 20 normal individuals were divided into 4 groups: G1- 15 HIV-1+ individuals, previously untreated or without HAART for at least six months and CD4+ < 350 cells/mm3; G2- 31 HIV-1+ individuals undergoing HAART without virological therapeutic failure (TF), G3- 43 HIV-1+ individuals undergoing HAART with TF, and GC- 20 normal individuals who served as controls for serum cytokines. Demographic, clinical and HAART data were reviewed, and Beta-2 microglobulin, serum cytokines (TNF-α, IFN-γ, IL-2, IL-4 and IL-10), HIV-1 genotyping, plasma viral load and CD4+ and CD8+ lymphocytes tests were performed.