This consultation was organized by UNICEF Headquarters and the Regional Office for Central and Eastern Europe and the Commonwealth of Independent States in collaboration with the Inter-Agency Task Team on HIV and Young People. The consultation focused on experiences in countries with low and concentrated epidemics where HIV infection is concentrated among men having sex with men (MSM), injecting drug users (IDUs), and those who sell sex. HIV infection among most at risk populations in countries with low and concentrated epidemics may be as high as 40-50 per cent, whereas it is as low as 0.1 per cent in the general population. The meeting aimed to facilitate the exchange of information across regions on country-level data collection regarding most at risk adolescents (MARA); identify ways to use strategic information to improve HIV prevention among MARA; and suggest ways to build support for MARA programming among decision makers.