This study investigates bioremediation of copper using copper-resistant bacteria, Stenotrophomonas maltophilia PD2. Living micro-organism was used to remove copper from aqueous solution. The influence of different parameters on bioremediation by S. maltophilia PD2, such as initial copper concentration and initial pH, contact time of the solution was studied. Response surface methodology (RSM) was applied for the optimization of the process parameters responsible for the bioremediation of copper ion effect and to evaluate the effects and interactions of the process variables. Based on the statistics analysis the optimum condition was found at pH 5.50, copper concentration 50.00 mg L-1, contact time 26.00 h and the copper removal was 90%. The optimization procedure of bioremediation showed a close interaction between the experimental and simulated values of copper removal. © 2013 Elsevier Ltd. All rights reserved.