Objective To obtain information about the similarities and differences in regulating different types of medical research in the European Union .Methods Web searches were performed from September 2009 to January 2011. Notes on pre-determined topics were systematically taken down from the web pages. The analysis relied only on documents and reports available on the web, reflecting the situation at the end of 2010.Results In several countries, regulatory legislation applied only to clinical trials on drugs and medical devices, in other states (...) various types of research were also regulated but by laws different from those concerning trials, and in many countries, some research areas were not controlled by legislation at all. In very few countries was all medical research handled similarly from a legal point of view. The number of research ethics committees in a single country varied from one to 264. Their areas of responsibility, working principles and length of time to grant research permission varied as well as the rules for obtaining informed consent from vulnerable groups. In 10 EU countries, there was no appeal mechanism after a negative decision by an REC. The RECs were not accountable to any organisation in five EU countries.Conclusions There is a need for a fundamental debate regarding whether and which kinds of changes are needed for the further harmonisation of medical research governance in the EU and how cross-country medical research could be facilitated in the future. (shrink)