Trace concentrations of bromine and iodine in food samples and certified reference materials (CRMs) were determined by an inductively coupled plasma-mass spectrometry (ICP-MS) technique after low-power microwave digestion and extraction into an aqueous quaternary ammonium hydroxide solution. The recovery after sample preparation was quantitative. The internal standard for the measurement of the analyte on ICP-MS was optimized in this study. The detection limits were 0.19 and 0.68 ng g(-1) for I and Br, respectively, when a 10 ng g(-1) Te solution as an internal standard was used, applying the signal of (125)Te. The high recovery and reproducibility are sufficient for the quantitative analysis of these elements, and the analytical procedure is recommended for the analysis of Br and I in various kinds of bio-samples.