In Spain, there is a need to improve chronic hepatitis C care among people who inject drugs (PWID). Injecting drug use is an important risk behaviour for hepatitis C virus (HCV) infection. Review of 28 sources of the relevant published literature mapped the size of the addiction-HCV population in Spain. Experts in opioid use disorder (OUD) treatment in Spain completed a consensus to define the population size, HCV prevalence and access or barriers to hepatitis C treatment for PWID populations. In Spain, over 300 000 individuals have a lifetime history of injecting drugs. Currently, 150 000 individuals in Spain have OUD; many have injected drugs. Each year, 80 000 individuals engage with treatment services for OUD. A proportion of this group continues to inject drugs. There is a high HCV prevalence in PWID – estimates of 60–80% in Spain. Uptake of hepatitis C therapy in PWID in Spain is limited; barriers include awareness of treatment pathways, advocacy for regular screening and effective joint care. There is an urgent need to address barriers to effective hepatitis C care for PWID in Spain. Practical and specific strategies including peer-led solutions, patient buddy systems and joint working models at the local level can make important short-term differences.