Chromium usually occurs in the (III) or (VI) oxidation state. Cr(III) is essential for mammalian systems to influence maintain several metabolic pathways. In contrast. Cr(YI) exerts toxic influence on biological systems and is strongly canccrogcnic. Cr(Vl) compounds arc usually highly soluble, mobile and bioavailable compared to sparingly soluble trivalent chromium compounds. Chromium is most often analysed using instrumental methods such as AAS or ICP. These methods are precise and sensitive but make determination of only total chromium. Possible content of Cr(VI) is estimated from the difference of total chromium content and Cr(III), which is analysed using photometric methods. This so-called "difference method" makes the calculated concentration of Cr(VI) is inaccurate. This paper describes sensitive and selective determination of Cr(VI) in various waters at ug/dnr' levels using a simple ion chromatography system with UV detector.