Introduction: In Mexico in public health institutions antiretroviral treatment is provided to patients with HIV / AIDS, although not always with the certainty that they take this medication. Adherence to treatment is probably the most important factor at the individual level that ensures adequate response to antiretroviral therapy. Objetive: To determine the adherence to antiretroviral therapy in patients with HIV/AIDS. Methodology: Descriptive, cross-sectional study in 62 patients with HIV / AIDS. It was used a personal data card and an instrument to measure psychological variables and adherence-to-treatment behaviors in HIV seropositive persons (VPAD-24) with Cronbach’s alpha of 0.7 and 0.8. Descriptive statistics in SPSS version-18 was used. Results: 72.6% of participants were male, mean age 36.5 years (SD = 9.0), predominant education level was high school 37.1%. The 90.3% of the sample studied adheres to antiretroviral therapy. Conclusions: The results of this study indicate a high adherence to antiretroviral therapy.