Social services are a range of publicly or privately provided services intended to aid disadvantaged, distressed or vulnerable persons or groups. These public services are set up to create more effective organizations, build stronger communities, and promote equality and opportunity. Religion and philosophy have tended to provide frameworks for the conduct of social welfare. Early few examples of systems that addressed social needs includes: the edicts of the Buddhist emperor Asoka in India and the sociopolitical doctrines of ancient Greece and Rome. The social services have flourished in the 20th century as ideas of social responsibility have developed and spread and they are involved in the benefits and facilities such as education, food subsidies, health care, police, fire service, job training and subsidized housing, adoption, community management, policy research, and lobbying. Substance use and misuse by adolescents are important issues that contribute to significant medical, psychological, and legal consequences at the time of use or later in life. The use and misuse of drugs by adolescent can be occasionally but a few can also be regularly. Reasons behind the use of drugs by adolescents are diverse and are common amongst adolescents residing in urban areas than those living in rural or suburban areas. 1. “For a long, the most commonly used illicit substance by adolescents has been marijuana and its rates of use among adolescents have increased significantly since 1991. Other commonly used substances amongst adolescents include alcohol, tobacco and designer drugs. Harm reduction is defined as interventions, policies and programs that seek to reduce the health, social and economic harm of drug use to individuals, communities and societies” (Rhodes et al 2010). “The focus or main goal of harm reduction programs and policies is to reduce harm due to drug use not necessarily reducing drug use. Harm reduction is considered by easy access to help and care, help on user’s terms with few conditions, a focus on how to decrease injury related to health, hygiene, sexual conduct, family, economy and a focus on anti-stigmatizing attitude” (Adnanes et al 2008). Social services have a huge role to play in the recovery intervention of adolescent drug users and also in preventing further drug use. In this thesis I will review the European social services, its various models, adolescents and drug use and the role of social services and social work in these adolescents with emphasis and focus on the harm reduction programs for these adolescents.