We are pleased this month to bring you a themed issue of the Journal of Evidence Based Medicine dedicated to the prospective registration of clinical trials. In 1988, Curt Meinert writing in the journal, Controlled Clinical Trials, hoped that “prospective registration will be the norm for all clinical trials by the time we enter the 21st century”. He wrote that this might be realised “only through a collective resolve and effort to bring it about” (1). More than two decades after Meinert's article, and a decade into the century, the establishment of national and international trial registries in many parts of the world has brought us much closer to achieving that aim, and the World Health Organisation's International Clinical Trials Registry Platform (ICTRP) allows many of these registries to be searched through a common interface. Since our last special issue on trial registration, two and half years ago, there have been many important developments and the number of trials available through the ICTRP has grown considerably. At the beginning of 2009, it contained 77,000 trials, with approximately one-third of these being open to new participants (2). Now, in the middle of 2011, a search of the ICTRP reveals 140,000 trials, of which 42,000 are currently recruiting. In this issue, we feature articles on two of the most recent additions to the list of primary registries that contribute to the ICTRP, from Brazil and Cuba. There are also articles on the national registries for clinical trials in China, Iran, Thailand, and Sri Lanka; as well as the international registry established by Current Controlled Trials which assigns the International Standard Randomized Controlled Trial Number (ISRCTN), the Pan-African Clinical Trials Registry based in South Africa and the ANZCTR which covers Australia and New Zealand. Alongside these descriptions of current registries, this issue's education section outlines some of the reasons behind the importance of registering trials and notes how prospective registration has recently been extended to cover systematic reviews, through the opening of PROSPERO by the Centre for Reviews and Dissemination at the University of York in England (3). You can also read, in her own words, about the experience of Kerry Dwan who recently led a Cochrane methodology review of studies that compared the content of the registration entries and protocols for clinical trials, with the content of the reports of their results (4). She highlights the worrying rate of inconsistencies between these sources of information on the methods used in trials and the need for greater awareness of the importance of ensuring that any changes between the plans for a trial and its conduct are clearly described and explained. Finally, in keeping with the focus of the Journal of Evidence Based Medicine on improving access to reliable knowledge by people involved in disaster risk reduction, planning and response, we should like to mention the ongoing needs assessment by Evidence Aid (5). An online survey has been launched to gather opinions on the role of systematic reviews and research in this arena, and to identify priority areas for the future development of Evidence Aid. The survey can be accessed from the main Evidence Aid website (http://www.EvidenceAid.org) and is available in Arabic, French and Spanish; as well as English.