HIV/AIDS is a leading cause of death worldwide. HIV/AIDS is not just a health problem; rather it is a societal problem with important social, cultural and economic dimensions. It attacks people in their economic and socially most productive years. Antiretroviral therapy has changed HIV infection from a fatal disease to a chronic illness. Success of the therapy highly depends on early diagnosis, regularity of treatment and safe sex behaviour. Social factors and lack of social support can affect or reduce the utilization of ART services from initiation of ART to lifelong ART treatment at ART centre. This book describes in detail the factors such as socioeconomic, demographic, knowledge and practice related to ART adherence of PLHIV, social support and positive prevention by using Information, Motivation and Behavioural skills model. Suggestions to improve the delivery system by the health care providers are also listed out in this book. Sociologists, policy makers and programme personnel of HIV/AIDS programme, public health specialists, academicians and researchers can get high benefit by make use of this book.