The effect of O-3 presence on NO2 sorption over Y-type zeolite ion exchanged with H+ was studied. The experiments with a gas-flow system have been performed where the profiles of NO2 sorption and temperature-programmed desorption were registered. Nitrogen dioxide was removed from a stream of humid air with dew point 0 degreesC by the sorbent saturated with moisture. The distinct influence of ozone presence on the characteristics of NO2 sorption/desorption has been observed. Significant enhancement of NO2 uptake has been obtained by the injection of O-3, which has brought about, as it seems, the formation of Stable nitrate anions within the sorbent. Also, the probability of the practical application of the observed effect has been considered.