Abstract Alien Fish (Synonyms: non-native, non-indigenous, allochthonous, and exotic) species have been introduced to the Mediterranean-Black Sea Basin via the Suez Canal, Gibraltar or in ballast water. The number of alien fish species increased recently in the Black Sea-Mediterranean Basin because of the opening of the Suez Canal, climate change and international shipping activities. The aim of this review is to compile all relevant data for the alien fish species in both the Black and the Mediterranean Seas. As a result a total of 160 alien fish species have been reported from the Black Sea-Mediterranean Basin. There are 67 species introduced from the Atlantic Ocean via the Gibraltar, three species of which are originated from the Boreal Atlantic, 86 species introduced from the Red Sea via the Suez Canal, four species of which are originated from the Pacific Ocean. The number of alien fish species increased 68.42 % between years 2002-2010. Some alien fishes mostly in the eastern Mediterranean were well colonized, recently, such as Indo-Pacific species Atherinomorus forskalii, Fistularia commersonii, Lagocephalus sceleratus and Etrumeus teres in the western Mediterranean. Regionally, there are 40 species of the Aegean Sea, three species from the Marmara Sea, five species from the Black Sea, 96 species from the eastern Mediterranean Sea, 26 species from the Ionian Sea, 36 species from the Tyrrhenian Sea, 14 species from the Algerian coasts, 43 species from the Alboran Sea, 21 species from the Adriatic Sea, six species from the Ligurian Sea, 10 species from the Gulf of Lion and 10 species from the Tunisian coasts were reported in total of 160 alien fish species.