Length-weight relationships were calculated for 48 fish species from İzmir Bay in the Aegean Sea, Turkey. A total of 3584 fish specimens were captured with beach seine, handline, fyke net, scoop net, castnet and trammel net in 2010–2014. The sample size ranged from three individuals for Squatina squatina to 140 for Mugil cephalus. R2 values varied between 0.95 for Pomatoschistus bathi and 0.99 for Argyrosomus regius, Chelon labrosus and Mugil cephalus. All regressions were highly significant (P < 0.001). Values of the exponent b in the length-weight regression (W = aLb) ranged from 2.750 for S. squatina to 3.514 for Syngnathus acus and the median value was 3.134 with 25–75% of the values ranging between 3.030 and 3.218.
