In this study, selectivity of trammel nets of 80 mm mesh size widely used for common dentex fishery in the South Aegean was estimated. Selectivity parameters were determined with Sechin (1969) method based on the maximum body and operculum girths. Biometric measure-ments of 97 common dentex specimens were taken and weight-length relationship was deter-mined. Minimum and maximum lengths were 18 and 77 cm, respectively. Average total length was 48.38 cm. In addition to net mesh size selectivity, length-maximum girth (Gmax) and length-operculum girth (Gc) relationships were determined. Optimum catch length of trammel nets with 80 mm mesh size for common dentex and selectivity factor were found as 28 cm and 7.