Abstract: We have performed a comparative theoretical study on the adsorption of nitric oxide (NO) on Zn₁₂O₁₂ and Mg₁₂O₁₂ nanocages in terms of their energetic, geometric, and electronic properties. It has been found that NO adsorption on the MgO nanocage is energetically more favorable than that on the ZnO one. In contrast to the ZnO nanocage, HOMO-LUMO energy gap (Eg) of MgO one is dramatically decreased in the presence of NO molecule so that it is transformed from an intrinsic semiconductor (Eg≈5.00 eV) to a p-type one (Eg≈1.93 eV). We have predicted that electronic and conductance properties of the Mg₁₂O₁₂ nanocage are sensitive toward NO molecule, thus it may be potential candidate in detection of NO molecules.