Metal oxynitrides with perovskite AMO 3¹x N x structure have been shown to exhibit promising optical, dielectric, magnetoresistive or photocatalytic properties. They are formally obtained from perovskite oxides via substitution of oxygen by nitrogen. However, due to the stability of the MO bond, only a limited number of nitrogen-doped perovskites AMO 3¹x N x and stoichiometric oxynitrides (AMO 2 N and AMON 2 ) has been synthesized and studied so far. Different case studies revealed that the oxidation states of the cations, the O/N ratio, as well as the anion ordering can significantly affect their properties. With the aid of density functional theory calculations, the effect of O/N anion ordering was investigated for a series of different metallic perovskite phases AMO 2 N (A = Rb, Sr, Y and M = Cr, Mo, W). Results indicate that well-defined cis-MO 4 N 2 octahedra in the structures are energetically preferred over trans-MO 4 N 2 octahedra, leading to zigzag MN chains in the materials.