Globally, there were an estimated 33 million [30.3 million__ampersandsignmdash; 36.1 million] people living with HIV in 2007(1). The introduction of highly active antiretroviral therapy has led to a significant reduction in AIDS-related morbidity and mortality.(3,4,5) Objective : To know the incidence and pattern of adverse drug reactions associated with antiretroviral therapy in our setup, we have planned this study in Anti Retroviral Therapy Centre with 400 patients taking antiretroviral therapy. Methodology: This is a continuous, longitudinal, prospective follow up study of 400 patients conducted in a single centre, ART Centre, Surat. A pretested semi-structured questionnaire was used. Pilot study was done in the months of April and May 2007. Later required numbers of patients were recruited and followed up for minimum period of eight months for observing adverse reactions. Then causality assessment was done using Naranjo__ampersandsign#39;s scale and WHO __ampersandsignndash; UMC probability scale. Information was collected about their clinical status, opportunistic infections, adherence to therapy and possible adverse effects in the previous month. Results: A total of 107 patients showed adverse drug reactions (ADR) due to antiretroviral therapy. Out of the different ADR__ampersandsignrsquo;s, skin rashes (7.25%), anemia (6.5%) and nausea/vomiting (5.5%) were common as compared to other reactions. Analysis: The data was analysed with the help of Excel and EpiInfo software (version. 3.2).