The website at http://www.briancoad.com/Species%20Accounts/Contents%20new.htm aims to be a guide to the freshwater fishes of Iran. There are no modern keys to this fauna, some available books are incomplete or cursory treatments or outdated, and the detailed and diverse scientific literature is widely scattered in time, languages and journals. Iran lies at a region of major zoogeographical interchange and has a diverse and interesting ichthyofauna about which comparatively little is known. An accurate identification is a pre-requisite for further scientific studies and this website aims to serve that purpose and to be an introductory guide to the fishes. The guide is aimed at a mixed audience, including scientists familiar with ichthyology to whom some introductory sections of this work will be superfluous, and those whose knowledge of fishes is embryonic or who may have limited access to literature sources. More information on this dataset can be found in the Freshwater Metadatabase - BFE_53 (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BFE_53).