As a result of rapid population growth and industrialization, wastewater generated in various sectors poses a threat to the environment and living things.Textile industry wastewater comes first among these wastewater sources.These wastewaters contain dyestuffs and different chemicals. These waters, which contain many impurities, must be treated well, otherwise they may cause serious problems in the environments where they are discharged. Various physical, chemical and biological methods are used for color removal in wastewater. However, due to the cost and low efficiency of these methods, researches are carried out on innovative and more economical methods. Among the new technologies, advanced oxidation processes (AOPs) are highly efficient new methods being studied for the purification of certain impurities that cannot be removed by general techniques. AOP methods include photocatalytic reaction with UV, ultrasound, Fenton/Peroxide, ultrasound sound waves and similar reactions. One of these methods is ozonation method. In this study, ozone decolorization of wastewater after disperse dyeing taken from textile dyehouse was investigated. In the determined procedure, the removal of color by ozonation method, which is one of the advanced oxidation methods for wastewater recipes after dyeing, was investigated and the color absorbance and COD values of the samples were examined and the results were evaluated.