Nitrous oxide (N 2O) is the fourth most prevalent greenhouse gas in the atmosphere after carbon dioxide (CO 2), methane (CH 4), and water vapor. This gas contributes most significantly to global warming since it decomposes with great difficulty in the atmosphere, even in low concentrations. Emissions of N 2O gas are known to have an impact 310 times greater than the impact of CO 2 on global warming. According to the Intergovernmental Panel on Climate Change, N 2O concentration in the atmosphere has increased by 46 ppb (17%) since 1750, and continues to increase. A biofilter works by draining the contaminated air flow through a porous medium in which contaminants in the air flow are adsorbed by biofilms; these contaminants are then oxidized to produce biomass, CO 2, H 2O, nitrate (NO 3 -), and sulfate (SO 4 2-). In addition, the biofilter supports the growth of microorganisms present in the porous medium. This research was conducted to investigate the performance of two types of a compost-based filter medium in 9 hours N 2O biofiltration, with N 2O flow rate variations and variations in water content levels of the filter medium. A biofiltration experiment was conducted to evaluate the effects of selected parameters on N 2O removal efficiency. The results showed that goat manure-based compost was more effective in reducing N 2O compared with cow manure-based compost, with the highest efficiency of 70.1%.