The identification of species of fish is an important theme to take into account for the correct labelling of fisheries products. In order to avoid possible fraud in labelling, a number of different technologies have been developed in recent years to comply with the regulations of the European Union (Regulation CE No 104/2000) indicating the need to label fisheries products with their scientific name so as to ensure traceability throughout the chain of processing and marketing. Within the European SEAFOODplus project, AZTI- Tecnalia has launched a DNA database scheme, free of charge. This database contains more than 700 references for the mitochondrial DNA sequences of the most important commercial species in Europe, including Gadidae family (e.g. cod), the Thunnus genus (e.g. tuna) and Merlucciidae family (e.g. hake). The database is a practical tool for validating techniques of identification in species of fish. It is based on DNA analysis by means of a dynamic system that enables the simplification of the handling of DNA sequences for establishing similarities and finding polymorphisms, etc. Thus, each DNA reference sequence is characterised (with a marker at the 3’ and 5’ ends) facilitating its location on the genome. Moreover, it is a useful source of information for developing new techniques of identification based on DNA analysis, enabling the comparison of results obtained in various laboratories.