Industrial waste gas emissions containing pyridine are generated from pyridine manufacturing industries, and in industrial operations where pyridine is used as a solvent, as an intermediate for synthesis and as a catalyst for a variety of applications. Pyridine has unpleasant fishy odor with an odor index of 2390 and waste gaseous emissions containing pyridine require proper treatment prior to discharge. A biofilter, packed with compost and wood chips and inoculated with Pseudomonas pseudoalcaligenes-KPN for enrichment of pyridine-degrading microorganisms, was operated on a continuous feed basis for a period of more than 2 years. The results indicate that the biofilter medium with optimal moisture content of 68% and an effective bed retention time (EBRT) of 28.50s could degrade pyridine effectively (>99%) at a loading of 434 g pyridine m(-3)h(-1). The treated waste gas was also found to be free from pyridine odor.