We have developed a new method for the determination of hexavalent chromium in waters that combines anion chromatography with the detection power of ICP-MS. The method eliminates false positives that might occur in spectrophotometric methods. It provides a method detection limit of 9 ng/L which is 30 to 40 times lower than EPA Method 7199. The interferences from matrix anions such as chloride and carbonate are minimal which makes the method suitable for difficult water matrices such as waste and sea waters.