Immunization is an essential health service which may be affected by the current COVID-19 pandemic. Disruption of immunization services, even for brief periods, will result in increased numbers of susceptible individuals and raise the likelihood of outbreak-prone vaccine preventable diseases (VPDs) such as measles. Today WHO issues guidance on immunization services during the COVID-19 pandemic. This document provides guiding principles and considerations to support countries in their decision-making regarding provision of immunization services during the COVID-19 pandemic and is reviewed and endorsed by the WHO’s Strategic Advisory Group of Experts on Immunization. The guidance includes advice on the importance of maintaining safe immunization services. If immunization services are disrupted, it is important to plan for urgent catch-up vaccination of missed children when physical distancing measures are lifted. The guidance further recommends temporary suspension of preventive mass vaccination campaigns and provides advice on conducting careful risk assessment before implementing outbreak response vaccination, with attention to appropriate protective measures to avoid transmission of the COVID-19 virus.