People with HIV have higher prevalence in the custodial settings as compared to the general population. HIV infection in many countries has been closely related to the use of illicit drugs via intravenous route. In Malaysia there are significant proportion of HIV infection are transmitted via this way. There was around 95% of HIV infected prisoners were heroin addict who injected themselves This is even more important when the use of illicit drugs has been criminalised. The criminalisation of illicit drug which has been the primary approach in tackling drug problems results in the difficulties in delivering health service to those have been detained due to the use of illicit drugs. There are growing positive evidence which shows medical and psychosocial modes of treatment for tackling drug related harms resulted in better outcomes. Issues of co-morbidity in those who use drug are also important consideration when providing mental health service to individuals with HIV infection. It is even more complex when these people are incarcerated These issues are discussed in this presentation. This will be based on researches (HARAPAN Project) which are undertaken in one of the prison facilities.