The invention describes a highly efficient catalytic pollution control process for removing N.sub.2 O from gaseous mixtures. The catalytic process, which is substantially unaffected by the presence of oxygen, comprises contacting an N.sub.2 O-containing gaseous mixture with a catalyst comprising a crystalline zeolite which, at least in part, is composed of five membered rings having a structure type selected from the group consisting of BETA, MOR, MFI, MEL and FER wherein the crystalline zeolite has been at least partially ion-exchanged with a metal selected from the group consisting of copper, cobalt, rhodium, iridium, ruthenium and palladium under conditions sufficient to convert the N.sub.2 O into gaseous nitrogen and gaseous oxygen.