The book is based on study entitled "Prevalence of substance use and correlates: A study in adult population ( 15 years) in Aligarh" conducted with the aim of determining the prevalence and pattern of various substances being used among adults ( 15 years) of Aligarh district and also the socio-demographic factors associated with substance use, in the field practice areas of the Department of Community Medicine, Jawaharlal Nehru Medical College Aligarh Muslim University, Aligarh. The book gives insight regarding current prevalence of substance use in study area and also throw light on socio demographic correlates of the risk behaviour.