Much research at the national and international level has been devoted to the development of several genetic methods for use in the characterization of fish stocks. We have developed a database that collates data from population genetic studies of fish. This database is accessible to researchers and control authorities on the Internet and should serve as a repository for genetic information of commercially important fish species. The prototype database has been developed in such a way that the new information can easily be updated by researchers in the field, who can submit their own data. The site can be found at http://fishgen.jrc.it.