The Fe/ZrO2 catalyst (1% Fe by weight) shows a strong adsorption capacity toward the nitric oxide (at room temperature the ratio NO/Fe is ca. 0.5) as a consequence of the formation of a highly dispersed iron phase after reduction at 500-773 K. Nitric oxide is adsorbed mainly as nitrosyl species on the reduced surface where the Fe2+ sites are prevailing, but it is easily oxidised by oxygen forming nitrito and nitrate species adsorbed an the support. However, in the presence of a reducing gas such as hydrogen, carbon monoxide, propane and ammonia at 473-573 K the Fe-nitrosyl species react producing nitrogen, nitrous oxide, carbon dioxide and water, as detected by FTIR and mass spectrometers, The results show that nitric oxide reduction is more facile with hydrogen containing molecules than with CO, probably due the co-operation of spillover effects. Experiments carried out with the same gases in the presence of oxygen show, however, a reduced dissociative activity of the surface iron sites toward the species NOx formed by NO oxidation and therefore the reactivity is shifted to higher temperatures.