In this study, discarded rates of the commercial red mullet (Mullus barbatus) gillnets made from different netting twine, monofilament and multifilament were presented. The nets were set near the shore which contains sea grasses (Posidonia oceanica) in Izmir Bay. These areas are sensitive habitats. During the fishing trials, totally 32 fish species have been caught, 21 of which were non-marketable. The rates of these non-marketable species are 77.8% and 22.8% in number for monofilament and multifilament gillnets, respectively. Serranidae and Labridae families were dominant in catch composition. The CPUE of the monofilament and multifilament gillnets for weight were calculated as 129.6 +/- 5.1 and 36.9 +/- 1.3 respectively. As a result, monofilament gillnets caught more non-marketable species than multifilament gillnets (P < 0.05; z=0.007). Because of the high rate of discarded species, it is not advisable to use monofilament gillnets near the shore, which contains sensitive habitats.