A combination of hydride generation with inductively coupled plasma atomic emission spectrometry (ICP-AES) after sample preconcentration using Chelex-I 00 resin was successfully applied to the determination of Pb in open sea-water where the concentration found ranged between 40 and 50 ng I-' and coastal sea water where the lead concentration was higher. The detection limit of the proposed method was 6 ng I-', which was about 100 times better than the methods using preconcentration such as solvent extraction or ion exchange, followed by ICP-AES with direct nebulization of the solution. The method was checked with a reference material (Nearshore Seawater, CASS-1, National Research Council of Canada) and the result was in good agreement with the certified value.