A simple, sensitive, and selective high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method in the negative-ion electrospray ionization (ESI(-)) mode was validated for the quantitation of bromate (BrO(3)(-)) in potato snacks. Ground snack specimens ( approximately 0.5 g/sample) are spiked with Br(18)O(3)(-), stable-isotope labeled bromate internal standard (IS), and vortexed with a mixture of distilled/deionized water (dd water) and heptane. Subsequently, the specimens are centrifuged, and a small portion of the aqueous extract is isolated, diluted with dd water (1:4), and analyzed by HPLC-MS/MS. The methodology has a quantitation range of 10-1000 ppb, an accuracy of 1.5-7.5%, and a precision of 5.2-13.4% across the concentration range.