In this paper, the tolerance and stability versus SO2 of Ba(0.9)A(0.1)Ti(0.8)Cu(0.2)O(3) (A = Sr, Ca, Mg) perovskite-type catalysts for NOx storage application have been analyzed at 400 degrees C. Characterization results show that only strontium and magnesium are introduced into the perovskite structure. From those data, it can be concluded that the incorporation of Sr into the Ba0.9Sr0.1Ti0.8Cu0.2O3 catalyst promotes the generation of new NOx adsorption active sites. On the contrary, for Ba0.9Mg0.1Ti0.8Cu0.2O3 catalyst, copper is segregated from the catalyst lattice to the surface due to the incorporation of magnesium into the B site of the perovskite. The partial substitution of barium in Ba0.9Sr0.1Ti0.8Cu0.2O3 and Ba0.9Mg0.1Ti0.8Cu0.2O3 catalysts increases the NOx Storage Capacity (460 and 415 mu mol/g.cat. in saturation conditions, respectively), stability and tolerance versus SO2 compared to the raw BaTi0.8Cu0.2O3 perovskite.