Abstract: In this study, mercury (Hg) levels in Mediterranean mussel (Mytilus galloprovincialis Lamarck, 1819) has been evaluated. The mussels are collected from six different regions of the coast of Bosphorus on seasonal basis from 2002 to 2004. The mussels are divided into two groups concerning their shell length. Hg levels were determined in the seasonal periods from each station and the heavy metal results obtained from the samples were expressed as the annual result of two different regions: The European side and Asian side of Bosphorus. The results reveals out that, there is severe pollution and deposition of mercury in the mussels living at the Bosphorus, at the same time it has been found that the pollution is worse at the European side comparing with the Asian shore.