The fundamental issue of the role of the Co 3d and 4s orbitals in the metal-ligand interactions of Co(III) complexes has been reexamined using density functional theory. It is suggested that the 3d and 4s orbitals take on a relative role depending on the symmetry-restricted covalency of a particular metal-ligand interaction. In all the [Co(NH3)(5)X]((3+n)+) complexes studied in this work, the contribution of the Co 4s orbital in the metal-ligand bonding is predominant when the interaction is less covalent whereas the converse is true for the Co 3d orbitals, The covalency of the metal-ligand interactions in Co(III) complexes depends entirely on the different degrees of participation of the Co 3d orbitals. This result rationalizes the observed Co-59 NMR trends reported earlier on [Co(NH3)(5)X]((3+n)+) complexes.