The crystal structure of Na2Mg2NiH6 as published by Kadir and Noreus (Inorg, Chem. 2007, 46, 2220-2223) is revised. While the reported space group symmetry and cell parameters are correct, the Mg and hydride positions need to be interchanged. Consequently, the tetrahedral [NiH4](4-) complexes are stabilized by both Na+ and Mg2+ ions and not by Na+ ions only, as was stated by the authors. The metal-hydrogen bond distances of the revised structure model differ by up to 0.6 angstrom from those reported and are more in line with those usually observed in these sorts of hydrides. An overview of the known cation configurations around solid-state [NiH4](4-) complexes is given.