Problematic dyes extensively used in different industries such as textile, paper, food, plastics and cosmetics have undesirable environmental effects. White rot fungi demonstrating effective extracellular enzyme system, which is capable of degrading dyes and various xenobiotics. The aim of this study was to optimize decolorization of reactive blue 19 (RB19) dye using Phanerochaetechrysosporium. A Box- Behnkendesign and Response Surface Methodology (RSM) were used to study the effect of independent variables, namely glycerol concentration (15, 20 and 25 g/L), temperature (27, 30 and 40oC) and pH (5.5, 6.0 and 6.5) on color removal efficiency in aqueous solution. From RSM-generated model, the optimum conditions for RB19 decolorization were identified to be at temperature of 20oC, glycerol concentration of 120/L and pH: 6.5. At the optimum conditions, predicted decolorization was 98 percent. The confirmatory experiments were conducted, which confirmed the results by 99.8 percent color removal. Thus, the experimental investigation and statistical approach enabled us to improve reactive blue 19 biodegradation process by Phanerochaetechrysosporium up to 1.25 times higher than non-optimized conditions.