Pharmacovigilance (PV) is the science relating to the detection, assessment, understanding and prevention of adverse effects, particularly long term and short term side effects of medicines. Spontaneous reporting of suspected ADRs is particularly important for anti-HIV drugs since many are licensed on the basis of limited safety data, and they are likely to be used in combination. Further, we believed that the detailed evaluation of the new information generated through pharmacovigilance activities is important for all the antiretroviral drugs to ensure their safe use. So we planned to provide an indirect measure of the quality of pharmaceutical care through identification of preventable ADRs and anticipatory surveillance of high-risk drugs used for the treatment of HIV/AIDS patients. We hope this book will give a strong platform for the people those who interested in Pharmacovigilance.