The Catalogue lists earthquakes that occurred in Italy between 461 B.C. and 1997, and earthquakes that occurred in the general Mediterranean area between the VIII century b.C. and the XV century. This version (CFTI5Med) features: the retrieval and formatting of over 23,000 original bibliographic documents, transcribed or printed, nearly 50% of those utilized in the CFTI5Med. These documents are now available on-line as fully searchable pdf files; a full geological reinterpretation, georeferencing and reprocessing of over 2,300 descriptions of earthquake-induced environmental effects, which are now all available and searchable in a user-friendly web-GIS environment; the elaboration of a number of texts and commentaries that were missing from the CFTI4Med version of the catalogue; a totally re-designed and more efficient web- and web-GIS interface. The new Catalogo dei Forti Terremoti in ltalia includes 1,259 earthquakes that occurred in Italy (98 of which are currently considered false). No commentaries on the main earthquake effects were available in the previous version of the catalogue for 87 of such events as they had not been updated with respect to the information supplied in Guidoboni e Comastri (2005) for the 1000 AD-1500 AD time interval. The commentaries concerning the most significant effects of Italian medieval earthquakes have now been elaborated and are available along with the information on more recent events. For the remainder of the earthquakes first presented with the CFTI4Med - those that occurred in the general Mediterranean area away from the Italian coasts - the new catalogue provides only the felt reports and basic epicentral parameters.