This checklist aims to reviews and summarize the results of the systematic and zoogeographical research on the Iranian inland ichthyofauna that has been carried out for more than 200 years. Since the work of J.J. Heckel (1846-1849), the number of valid species has increased significantly and the systematic status of many of the species has changed, and reorganization and updating of the published information has become essential. Here we take the opportunity to provide a new and updated checklist of freshwater fishes of Iran based on literature and taxon occurrence data obtained from natural history and new fish collections. This article lists 288 species in 107 genera, 28 families, 22 orders and 3 classes reported from different Iranian basins. However, presence of 23 reported species in Iranian waters needs confirmation by specimens. The most diverse order is Cypriniformes (171 species, 59.40%), followed by Gobiiformes (42 species, 14.60%), Cyprinodontiformes (17 species, 5.90%), and Clupeiformes (11 species, 3.82%). Eighty-eight endemic species (30.56%) in 7 families and 26 exotic species (9.03%) in 9 families are listed here. Among 288 reported species, 163 (56.6%) species are Not Evaluated (NE), 93 (32.3%) Least Concern (LC), 11 (3.8%) Vulnerable (VU), 8 (2.8%) Data Deficient (DD), 7 (2.4%) Critically Endangered (CR), 3 (1%) Near Threatened (NT), 1 (0.3%) is Endangered (EN) and 1 (0.3%) Extinct in the Wild (EW) of the red list of IUCN. The only reason for this high number of not listed and least concern species in the IUCN Red List is lack of information about the species at national and global levels. This shows the necessity of reconsideration of global categories and application of the IUCN Red List criteria at the national level. Considering the number of endemic fishes (88, 30.56%) in Iran, the first step should be preparing an endemic national assessment for inclusion on the IUCN Red List. Over the last ten years, some native and exotic fishes have been translocated or introduced into natural water bodies. Aquaculture, sport fishing, control of malaria, ornamental purposes, research activities, demonstration in national fairs and accidental introduction are the main reasons for these introductions. Here, we report presence of the Alligator gar, Atractosteus spatula , as an introduced predatory fish from Marivan Lake which seems to have been released from an aquarium. In this checklist, additional, problematic species are also listed, the English/common name of each species is provided, the etymology of each genus is given, the conservation status of each species is given and the bibliographic list of most of published literature on the systematics of inland fishes is mentioned. The provided information will be necessary for the development of competent and pragmatic management plans and effective conservation policies.