The Institutional Review Board (IRB) examines the propriety of continuing clinical trials based on adverse event reports. However, since such a large number of adverse events are reported, both in Japan and other countries, it is a tremendous amount of work for a member of IRB to examine all the reports provided and it takes much time. In order to help the IRB be as efficient as possible in its activities, we conducted an investigation into the management of adverse event information at the University Hospital, Ryukyu University, between April 2002 and March 2003. The number of adverse events reported was 829 and among them, new, previously unknown adverse events accounted for 30.9 percent, and those from outside Japan for 96.6 percent. This indicates that examination could be more efficient and quicker if preference were given to such new adverse events from outside Japan. Thus, in order to assist the IRB, pharmacists should prepare a table of adverse events, in which they are categorized as known or unknown and also according to source, depending on whether they occurred in Japan or overseas.