A laboratory scale biofilter inoculated with Pseudomonas putida (MTCC 102) was used for degradation of toluene present in air. Wood charcoal was used as the filter media and a layer of glass beads (6 mm) was used for improved air distribution. The biofilter was operated continuously for a period of 5 months at four different flow rates - 0.06, 0.12, 0.18, and 0.24 m(3) h(-1), with inlet concentration of toluene ranging from 0.04 to 4.5 g m(-3). Air having toluene vapor was fed to the biofilter at various loadings ranging from 30.6 to 1104.5 g m(-3) h. The removal efficiency was obtained in the range of 70-99.5%. The maximum elimination capacity of 872.5 g m(-3) h(-1) was observed at the inlet load of 1104.5 g m(-3) h(-1). Wood charcoal was found to an effective biofilter media for toluene biodegradation. (C) 2010 Elsevier Ltd. All rights reserved.