In recent years, researchers have put a considerable effort to decrease the emission of harmful gaseous pollutants to the atmosphere. Although conventional wet scrubbers are being widely used to remove harmful gases, they have low removal efficiencies. This study reports the effect of some operating conditions on simultaneous removal of NO, NO2, SO2, and CO2, using a novel swirl wet scrubber system. The gaseous pollutants were absorbed into NaOH solution. As the absorbent media was circulated continuously for removal purpose, therefore the production of chemical wastes were minimized. The effect of absorbent concentration, gas flow rate, and liquid flow rate were investigated. The best efficiencies of NO, NO2, SO2, and CO2 simultaneous removal were 77, 88, 100 and 80%, respectively, with 2%, w/v NaOH as the scrubber medium. A comparison between this study and literature data shows that the liquid-gas flow rate ratio (F-L/F-G) in the novel scrubber of this work is much smaller than other gaseous pollutant removal systems. Therefore higher removal efficiency is obtained based on the same liquid flow rates. (C) 2011 Elsevier B.V. All rights reserved.