The cross-sectional descriptive study was done on 400 injection drug users (mUs) in 02 methadone treatment centers in Hanoi city. The study results show that: average initial dose for patients participating in the study is 20mg/day
average maintenance dose is 10Smg/day. The frequency of daily heroin use of patients is considerably reduced: pretreatment frequency is 1,24 times/day, dose-finding trial frequency after 7 days is 1,07 times/day, after 30 days: 0,33 times/day, after 3 months: 0,08 time/day. The rate of patients being transferred to other health services: antiretroviral therapy is 44,5 percent
opportunistic Infection treatment is 30,8 percent, clean needle provision is 21,3 percent
voluntary counseling test is 8,3 percent. These are preventive intervention in order to reduce HIV prevalence among injection drug users.