Haloacetic acids are non-volatile disinfection by-products of water formed in the reaction between chlorine-based disinfection agents and naturally occurring organic matter in water. Their maximum proportions in water are regulated by the Regulation on compliance parameters, methods of analysis and monitoring of water intended for human consumption (NN 64/23). Monitoring the proportion of disinfection by-products, i.e. haloacetic acids, is important because of their potential impact on human health. In this paper, a modified method for the determination of haloacetic acids in water is described, which is based on the extraction of haloacetic acids from a water sample into an ether layer, followed by the methylation of haloacetic acids with acidic methanol into the related methyl esters and the determination of haloacetic acids proportion in the sample extract by gas chromatography with an electron capture detector. The developed method was modified through validation parameters and it was found that the method is applicable on real water samples. The determination of haloacetic acids in water using the set method was performed out on water samples for human consumption from the area of Osječko baranjske county and the city of Zagreb. The total proportion of five haloacetic acids in the samples ranged from 1.59 μg/L to 21.50 μg/L, which represents values below the maximum allowed concentration of water pollution intended for human consumption.