Methods for the determination of As, Cd, Pb, Hg and Sn by electrothermal atomic absorption spectrometry in marine sediment slurry samples were developed. Triton X-100 was used as surfactant to stabilize the marine sediment slurry. Palladium or a mixture of palladium and magnesium nitrates was used as a chemical modifier. With the use of these modifiers it was possible to stabilize As, Cd, Pb, Hg and Sn to temperatures of 1200, 700, 900, 200 and 1300°C respectively, and the optimum atomization temperatures were 2300, 2500, 2500, 1450 and 1900°C. Precision and accuracy of the method were investigated using the marine sediment reference material PACS-1 (National Research Council Canada). The detection limits were 44, 0.08, 60, 70 and 57 μg kg −1 for As, Cd, Pb, Hg and Sn respectively.