Nebalia mediterranea sp. nov. (Crustacea, Leptostraca) is described from the Aegean coast of Turkey and Northern Cyprus. The new species is closely related to other sympatric species in the eastern Mediterranean, N. strausi and N. kocatasi, according to general body appearance. The new species differs, however, from other Nebalia species in having a rostrum about 2.5 times as long as wide, the antennular scale is clearly more than twice as long as wide, the fourth article of the antennule has only one short thick distal spine, the third article of the antenna has three similar spine-like setae on external lateral face, the first article of the second maxilla endopod is 1.2 times as long as the second article, the exopod of the second maxilla is longer than the first article of the endopod, pleonites 5–7 have distally rounded to slightly truncated denticles along posterior dorsal borders, the protopod of pleopod 4 has 4 serrations along posterior border, and the terminal seta of the uropods is about 1.8 the length of rami.