Introduction: Registration of clinical trials at inception could play an important role in research, by avoiding duplication of trials and serving as a source of information on the existence of clinical trials for those wishing to perform overviews. In order to fulfill their role efficiently those registries should have information about all trials, but existing registries are not exhaustive, mainly because registration is made on a voluntary basis by the investigators and/or sponsors. Registration is an additional administrative proceedure which is seldom incorporated in the sponsors' standard operating procedures. One solution to this problem is to identify a place where all protocols are centralized and, since they are all submitted to an ethics review board for approval, these boards could be an invaluable source of information about what trials are being done.

Discussion: One of the objectives of our project, on the feasibility of clinical trial registries in Europe, was to assess the attitudes of the ethics review boards to providing this information. We received 115 replies from 281 questionnaires sent to ethics review boards in 7 European countries. More than 70% replied that they would be willing to communicate information about the trials they review. There seem to be a general agreement that clinical trial registries should be funded and supported by governments. However, in 2 countries (Belgium and France), the ethics committees are not allowed by law to disclose information to outside bodies. Thus registration through ethics committees will require a European directive to override national laws.