A newly developed method for the determination of bromine (Br) and iodine (I) in low- to high-salinity aqueous samples by ICP-MS was established. Matrix related isobaric interferences ((ArK)-Ar-40-K-39 and (ArArH)-Ar-40-Ar-38-H-1 on Br-79) have been quantitatively estimated in the kinetic energy discrimination (KED) operation mode and the standard (STD) mode; it was shown that such interferences can be efficiently eliminated using the KED mode with He as a collision reaction gas. In addition, samples with high salt concentrations were analysed after pre-treatment using H-form cation-exchange resin with low dilution factors (10 or 20), rather than the high dilution factors (>200) reported in previous studies. The values for the total procedure blank of Br and I from this process were 0.784 and 0.015 mu gL(-1), respectively. The Br and I limits of detection (LOD) and spiked recoveries for this ICP-MS method were 0.1104 and 0.0013 mu g L-1 and 98.9-100.9% and 98.0-102.9%, respectively. The present method was successfully applied for the rapid and direct determination of Br and I in seawater and other aqueous samples.