Bromate is well known by-product produced by the ozonation of drinking water; the allowed concentration for human consumption has to be regulated to few μg/dm3 ranges. A method using ion chromatography has been developed, which will quantify bromate on this level, even in the presence of high levels of common anions such as chloride, nitrate and sulphate. The present article presents results of study of bromate determination in drinking water by two ion chromatographic methods. First was a direct method according to ISO 15061 with conductivity detector and limit of detection 4,5 μg/dm3. The second was new post-column derivatization reaction to produce tribromide ions, which was detected by UV detector. Limit of determination in this method was 0,5 μg/dm3. Both these methods are suitable to determination of bromate anions, because acceptable contents of bromate in drinking water in UE countries are 10 μg/dm3.