Abstract The biofilter packed with pressmud and inoculated with activated sludge obtained from pharmaceutical industry wastewater treatment plant was employed for the removal of ethyl acetate and xylene in this study. The effect of process variables like gas flow rates (0.03, 0.06, 0.09 and 0.12 m3 h-1), inlet concentration of ethyl acetate (1.75, 3.0, 7.0 and 10.5 g.m-3) and xylene (0.2, 0.4, 0.6 and 1.2. g.m-3) on the performance of biofilters was validated. The removal efficiency exceeded 97% for ethyl acetate at inlet concentrations up to 3.0 g.m-3 and 95% for xylene at inlet concentrations up to 0.4 g m-3. The maximum elimination capacity of 165 g m-3 h-1 and 66 g m-3 h-1 for the mixture of ethyl acetate and xylene were obtained. A steady state mathematical model was tested and proved to adequately describe the experimental results at the two operating regimes for both ethyl acetate and xylene.