This study evaluated the treatment performance of three types of buffer materials in a biofilter system to control odor-causing gases. The anaerobic decomposition of protein-rich organic compounds from fish raw materials and organic waste produces odors. The biofilter adsorbs odorous gases onto a biofilm and is biodegraded by microorganisms into simpler, less toxic compounds. Odor removal efficiency results in about 91-98% for ammonia gas (NH3), from 85% to 95% for hydrogen sulfide (H2S), from 78% to 100% for carbon monoxide (CO), and about 80% for carbon dioxide (CO2) gas. Compost buffer materials with coconut fiber particles have a slower adsorption time to saturation after 45 minutes than compost and compost with activated carbon after 35 minutes, respectively. Biofilter system can handle a wide spectrum of odor-causing gases and is environmentally friendly