Over the past two decades, HIV infection has been added to the serious risks of injection drug use, and the diffusion of HIV associated with drug injecting not only creates medical and social problems for the millions of injecting drug users worldwide but for society at large. Yet many drug dependent people living with HIV/AIDS do not enjoy equitable access to HIV/AIDS treatment, care and support services for HIV/AIDS as a result of stigma and discrimination, of their own reluctance to seek treatment, and of the unavailability of HIV/AIDS treatment in programmes for injecting drug users. This guidance document, built on expert advice and developed in consultation with UNAIDS, articulates the central principles for treatment and support of HIV-positive injecting drug users.