Records of 185 amphipod samples taken in Iran, both in the brackish Caspian Sea and in fresh waters belonging to the Caspian drainage system and the Central Basin. Twenty-nine species are represented (25 Gammaridae, 1 Pontoporeiidae, 1 Gammaracanthidae, 2 Corophiidae), of which 1 species of Obesogammarus, and 6 species of Gammarus (all from inland waters), 1 species of the new genus Scytaelina, and 1 species of Derzhavinella (both from the brackish Caspian Sea) are new to science, Obesogammarus turcarum, Gammarus imberbus, and G. syriacus are new to Iranian continental waters, whereas Gammarus aequicauda and Pontogammarus borceae are new to the Caspian Sea.