Dil Deresi stream is a highly contaminated stream passing through the most heavily industrialized area of lzmit Bay. In this research, surface sediments in the < 63-mu m, fraction collected from 34 sites at western part of lzmit Bay, Northeastern Marmara Sea, Turkey were analyzed by ICP-AES for Al, As, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sn and Zn. Metal concentrations were compared with the marine sediment quality standards (SQS) and literature data to assess the pollution status of the sediments. Enrichment factors (EFs) were calculated to assess whether the concentrations observed represent background or contaminated levels. The analysis revealed three groups of elements: (1) Sri is the most enriched element; (2) As, Cd, Ph and Zn are minor enriched elements; and (3) Co, Cr, Cu, Fe, Mg, Mn and Ni are at background concentrations. The distribution maps of the concentrations and enrichment factors for all heavy metals were also produced as a contour plot based on Geographic Information System (GIS) technology. (c) 2006 Elsevier Ltd. All rights reserved.