The number of heroin users in Greece in 2010 is estimated to be 22,515. Approximately 70 % of them live in Athens Metropolitan Area. For the same reference year, the estimated number of injecting drug users (IDUs) in the general population, 15–64 years old, is estimated to be 9 439. The majority of IDUs (52 %) belongs to the 25–34 age group, while 28.5 % are older (Greek Reitox focal point unpublished data). According to data of high reliability, the prevalence of hepatitis C virus in IDUs is estimated to be 50.2 %, while the prevalence of anti-HBc is estimated to be 20.5 % and HBsAg is estimated to be 2.5 %. The prevalence of anti-HIV was relatively low during the previous decade at 0.5 % (0.3– 0.8) (1).