The interaction of a nitrosyl hydride (HNO) molecule with B12N12 nanocage was explored by means of density functional calculations. It was found that HNO prefers to be adsorbing on a boron atom of the cage with adsorption energy of -0.65 eV. This adsorption process significantly shifts the HOMO-LUMO gap (Eg) of the cage to lower energies, thereby reducing Eg of the cage from 6.84 to 2.45 eV. Ti...