Azo dyes, which show great variety in color, constitute the largest group of synthetic dyes. There are more than 3000 types of azo dyes, which are used for various purposes in the industry. Azo dyes should be paid special attention because of their high color densities and possible mutagenic effects on the living entities of the environment. In this study, the removal of color, COD and aromatic group from one of the azo dyes, Remazol Red RR Gran, had been carried out by using one of the white rot fungi, Phanerochaete chrysosporium. Experimental studies were performed in a growth media containing different amounts of dye and glucose. Color measurements were conducted at 525 nm by a spectrophotometer (Novespec H), in the visible light spectrum, while aromatic group measurements were carried out using Jenway 6105 UV/Visible spectrophotometer. Color measurements have been made using values of indexes of transparency parameter. Values of indexes of transparency = DFZ (DurchsichtsFarbZahl) in accordance with the EN ISO 7887 standards were obtained by taking absorbance at 436, 525 and 620 rim. DFZ values were calculated from these measurements. Measurements were taken at 525 nm for Remazol Red RR Gran. COD experiments were carried out with the standards explained in APHA 5220 B (open reflux, titrimetric method). As a result of this study, the values of the removable color concentration were determined as 10 mg/L and lower. The optimum medium glucose concentration was determined to be 2 g/L. During color removal processes, aromatic group measurements were taken in samples in the UV region at 280 nm wave length. As a result of the measurements, it was revealed that certain amount of aromatic group remained in the model wastewater at the end of the process.