Harm reduction centres are often the only point of access to health and social services for many PWUD. Preliminary research on the effects of the COVID-19 pandemic on drug services and PWUD has noted decreases in available harm reduction services. European harm reduction services needed to be innovative and adapt very rapidly in response to the fast-changing landscape of the pandemic and its associated national control measures. Frontline harm reduction workers play a crucial role in public health response during COVID-19 and are instrumental in implementing these rapid-scale changes required to keep vital services operational. Their experiences during the pandemic provide critical data to understanding the effect of the pandemic on the vulnerable population of PWUD and the health services they depend on. This Correlation European Harm Reduction Network (C-EHRN) report on the impact of COVID-19 on vital harm reduction services seeks to bring these voices of front-line workers at drug consumption rooms (DCR’s), harm reduction outreach teams and PWUD themselves to highlight their experiences during the COVID-19 pandemic.