Croatia is one of the few countries rich in water. In an effort to preserve it is water resources and manage them sustainably, the Law on Waters (NN 107/95) and associated regulations. According to the current decision of state water quality in rivers near the town of Karlovac belongs to the secong category, and this final work explores the issues of drainage and waste water treatment of colored waste water by UV radiation. Colouring is one of the most visible indicators of water pollution. The presenc of dyes, even in low concentrations is visible and is not acceptable. The discharge of colored waste water is not only destroying the aesthetic nature of the receiver, but the colored substances are often toxic to theaquatic ecosystem. Althouh quite a number of technologies includes known methods of wastewater treatment, very few of them are based on advanced oxidation processes and UV treatment (UV, UV/H2O2, UV/O3, UV/h2O2/O3,). For these processes are determined by the optimum conditions for maximum efficiency of the decomposition of organic pollutants , based on changes in environmental indicators : the content of total organic carbon ( TOC ) content of adsorbed organic halides ( AOX ). The main objective of this study was to evaluate the effectiveness of tretment of colored waste water advanced UV radiation. The final work in more detail are developed characteristics of all types of waste water and method od UV radiation for the treatment of colored waste water.