Initial adsorption of NO2 on Ag(111) at 86 K is dissociative and gives rise to the formation of adsorbed O and (NO)(2) dimers. Subsequent adsorption is complex leading to the formation of NO3, NO and N2O3 which coexist on the surface with the O and (NO)(2). Further adsorption then leads to the formation of multilayers of N2O4. The multilayers are seen to desorb at 140 K, in agreement with previous observations.