Response surface methodology (RSM) involving central composite design (CCD) was employed to optimize the concentrations of different media components for growth and Cr (VI) removal (100mgl(-1) initial concentration) by Aspergillus lentulus AML05 at pH 6.5. The interaction between five variables i.e. glucose, K2HPO4, MgSO4, yeast extract, NH4NO3 was studied and modelled. The statistical analysis of the results showed that in the range studied, yeast extract had a significant effect on Cr (VI) removal and production of fungal biomass. The optimum combination predicted via RSM was confirmed through experiment, whereby almost complete removal (99.8%) of Cr (VI) was obtained within 120 h. The validation of these results in terms of field applicability was also tested by treating industrial effluent supplemented with key media components. (C) 2008 Elsevier B.V. All rights reserved.