Bioaccumulation of heavy metals (Hg, Cd, Pb, As, Cu, Zn) in Manila clams (Ruditapes philippinarum) was studied with respect to their concentrations in sediments and water column. The heavy metal concentrations in the intertidal sediments of the western coast of Korea were low compared to other coastal areas of the Korea. Generally Manila clams collected on the western coast of Korea contained more As and Cu than in mussels. Manila clams accumulated other trace elements in the approximately the same amount as in mussels. Heavy metal concentrations in the tissues of Manila clams increased with increasing shell length.