The present paper deals with a new method of reducing the emission of NOx during the combustion of oil, making use of bifractional atomization. Theoretical investigations have shown the possible reducing role of large droplets. This theory was verified on a test stand with a power rating of 50 kW. The results obtained confirmed the abatement of the emission of NOx by about 20-30% without any significant increase of the CO emission. The method suggested in this paper may be applied together with other methods of decreasing the NOx emission.