In the present study, fish and mussel samples from Izmir bay of Agean sea were studied for their mutagenic potential in TA98 and TA100 strains of Salmonella typhimurium using Ames test (plate incorporation assay) without metabolic activation. Black gobby (Gobius niger) samples were collected from Bostanli and Pasaport locations and mussel (Mytilus galloprovincialis) samples were collected from Alsancak, Alsancak harbour, Alaybey Shipyard, Karsiyaka, Bostanli, Goztepe, Konak and Pasaport locations on Izmir bay. Extracts were obtained from hepatic and muscular tissues of black goby and whole soft parts of the mussels. Obtained extracts were studied for mutagenicity using the Ames test with S. typhimurium TA98 and TA100 strains. According to results of the present study, mutagenicity was observed in liver extracts of the fish from Pasaport location whereas no mutagenicity was observed in liver and muscle extracts of fish from Bostanli location. Among the extracts of mussel samples collected from 8 locations only those from Alsancak Harbour were observed to possess weakly and directly mutagenic effects on S. typhimurium TA98 (frame shift mutations).