Response surface methodology involving three variables with five level second order central composite experimental design was employed to optimize conditions for maximum dye removal by Aspergillus lentulus FJ172995. The interaction between three variables; glucose, urea and initial dye concentration was studied and modeled for two responses: dye removal and biomass production. The results indicate that urea is the main factor influencing dye removal whereas glucose plays a major role in biomass production. Also, initial dye concentration has depreciative effect on dye removal thereby suggesting that for the treatment of effluent containing higher concentrations of dye, nutrient input should be increased. A high dye removal efficiency (99.97%) and high uptake capacity (97.54 mg/g) was obtained in 24 h using optimum process variables. (C) 2010 Elsevier B.V. All rights reserved.