Öz Colloidal palladium is a prospective modifier for electrothermal atomic absorption spectrometry (ETAAS). Owing to high effectiveness of metallic palladium in the stabilization of volatile analyte compounds, colloidal palladium modifier is very robust in its action. In the presence of colloidal palladium, interference-free determinations of As, Sb and Pb are possible up to at least 450 µg of chloride ion or 40 µg of sulphate ion (as corresponding sodium salts) in the atomizer. Colloidal palladium was used for the direct determination of As, Sb and Pb in a spiked sea water sample (from Bosphorus channel near Istanbul) by means of the calibration graphs prepared with pure analyte solutions. The detection limits for As, Sb and Pb in a sea water matrix calculated according to 2σ criteria are 5.4 ng ml-1, 3.6 ng ml-1 and 1.1 ng ml-1, respectively (for sample volume 10 µl). In unspiked sea water, the contents of As, Sb and Pb were found to be below the detection limits. Recoveries of spiked analytes (25 ng ml-1 and 50 ng ml-1) were in the region of 98-112% depending on the nature of analyte and the concentration of spike