The invention relates to a method for reducing the concentration of nitrogen oxides in waste gases released dating the production of organic amino compounds, wherein an organic compound is first reacted with NOx and/or nitric acid to form an organic nitro compound with the formation of an NOx-containing waste gas stream and the organic nitro compound is converted to the organic ammo compound by means of hydrogen-containing reaction gas, the reaction of the organic nitro compound with the hydrogen-containing reduction gas taking place with the formation of a hydrogen-containing waste gas stream, the method being characterised in that the NOx-containing waste gas stream is combined with the hydrogen-containing waste gas stream and/or an externally supplied hydrogen stream and is reacted at a temperature of 800 to 1700° C. for the at least partial reduction of the NOx concentration. The invention additionally relates to an apparatus for carrying out the method.