ECRIN (https://ecrin.org/), the European Clinical Research Infrastructure Network, is a not-for-profit organisation that supports the conduct of multinational clinical trials in Europe. The ECRIN team is based in Paris (headquarters), and has local experts (European Correspondents) in each Member and Observer country across Europe (https://ecrin.org/members-observers). Although many clinical trials are conducted on a national level, sometimes clinical trials have to go across borders. Without excluding industry-sponsored studies, ECRIN focuses its work on the conduct of investigator-initiated trials, across all disease and topic areas. It helps researchers with the set-up and management of their clinical trial in the multinational setting. It does this from the trial planning and the design, through to the operational trial management. It collaborates on the protocol, it overcomes regulatory, ethical and language barriers, and supports the researchers with the development of tools, methods and partnerships. ECRIN’s organizational model is based on country membership. Countries can either be full Members or Observers. Current Member countries include Czech Republic, France, Germany, Greece, Hungary, Ireland, Italy, Norway, Portugal, Poland, Spain, and Switzerland, and Slovakia is an Observer country.