INTRODUCTION: Antiretroviral therapy(ART) is effective in decreasing AIDS related deaths but it is associated with many adverse drug reactions(ADRs) which are leading to non–adherence to treatment. AIM: We sought to study ADRs, their variations with duration of treatment and also their causality and preventability. METHODOLOGY: A retrospective study was done over a period of four months on 500 patients attending ART center at Government tertiary hospital, Hyderabad. RESULTS: Out of 500 patients, 91% have experienced at least one type of ADR with majority affecting musculoskeletal system. A total of 1011 ADRs are reported by 455 patients. Females are found to be more susceptible to ADRs. According to causality and preventability scales, 76% of ADRs are probable and 27.2% are definitely preventable. CONCLUSION: To improve ART medication compliance, active screening for ADRs and educating patients may help in their early detection and prevention.