Introduction: Pharmaceutical care improves medication adherence that is why is important that the pharmacist uses instruments to evaluate and improves it through pharmaceutical intervention at pharmaceutical care. Objective: To evaluate the impact of the pharmaceutical intervention in the improvement of the medication adherence of the patients with HIV and AIDS, and to identify the factors that infl uence on medication adherence and which one could be modifi ed by the pharmaceutical intervention during pharmaceutical care. Methods: Pharmacotherapeutic follow-up was realized for 23 months to 52 patients, older than 18 years, with antiretroviral treatment for up to three months, consent informed was obtained from patients. Medication adherence was evaluated with CEAT-HIV (questionnaire to evaluate the adhesion to the antiretroviral treatment) at the beginning and at the end of the study (6...