In the course of the presently reported study, covering the Homa Lagoon, Izmir Bay, Turkey, we collected a total of 2690 fish specimens belonging to 15 families and representing 29 species: Anguilla anguilla (Linnaeus, 1758); Atherina hepsetus Linnaeus, 1758; Atherina boyeri Risso, 1810; Belone belone (Linnaeus, 1761); Blennius ocellaris Linnaeus, 1758; Sardina pilchardus (Walbaum, 1792); Aphanius fasciatus (Valenciennes, 1821); Engraulis encrasicolus (Linnaeus, 1758); Gobius niger Linnaeus, 1758; Pomatoschistus marmoratus (Risso, 1810); Pomatoschistus minutus (Pallas, 1770); Zosterisessor ophiocephalus (Pallas, 1814); Dicentrarchus labrax (Linnaeus, 1758); Chelon labrasus (Risso, 1827); Liza aurata (Risso, 1810); Liza ramada (Risso, 1827); Liza saliens (Risso, 1810); Mugil cephalus Linnaeus, 1758; Mullus barbatus Linnaeus, 1758; Mullus surmuletus Linnaeus, 1758; Syngnathus acus Linnaeus, 1758; Syngnathus typhle Linnaeus, 1758; Diplodus annularis (Linnaeus, 1758); Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817); Lithognathus mormyrus (Linnaeus, 1758); Sarpa salpa (Linnaeus, 1758); Sparus aurata Linnaeus, 1758; Platichthys flesus (Linnaeus, 1758); Solea solea (Linnaeus, 1758). The fish were weighed, and measured and their length-weight relations were determined. Samples were collected during 2009-2010 using four different types of fishing gear (beach seine, fyke nets, barrier trap, and trammel nets; mesh size: 25, 28, and 30 mm) that allowed both adult and juvenile specimens to be captured. Significant length-weight relations were found for all species. The exponent b varied between 2.753 for Pomatoschistus marmoratus and 3.650 for Aphanius fasciatus (mean value = 3.115). The length-weight parameters of the same species may be different in the population because of feeding, reproduction activities and fishing etc. Therefore, we need to know length-weight relations of fish, which are captured in a given place in a certain period of time. Length-weight relations for 5 out of the 29 fish species are presented for the first time from Homa Lagoon in the Turkish Aegean Sea.