People who use drugs are heavily affected by HIV, hepatitis C (HCV), and tuberculosis (TB) and are often neglected in countries’ and cities’ responses to the epidemics. There are effective means to prevent and treat HIV, HCV and TB among people who use drugs, but resources (financial, human and material) are often not adequately invested to make them accessible. The reasons for this are multifaceted and include criminalization, stigma, discrimination and denial of basic human rights to people who use drugs. This IDUIT Brief Guide for People who Use Drugs is intended to outline the key concepts of Implementing Comprehensive HIV and HCV Programs with People who Inject Drugs: Practical Guidance for Collaborative Interventions (the IDUIT) related to prevention, treatment and empowerment with regard to HIV and HCV, and point to how activists and professionals from among the community of people who use drugs might promote better policy and practice.