The details of a systematic carbon 13 nuclear magnetic study of cobalt(III) complexes with the tetraamine ligands 1,8-diamino-3,6-diazaoctane (2,2,2-tet), 1,9-diamino-3,6-diazanonane (2,2,3-tet), 1,9-diamino-3,7-diazanonane (2,3,2-tet) and 1,10-diamino-4,7-diazadecane (3,2,3-tet) are presented. Carbon 13 NMR was found to be an extremely sensitive probe of the stereochemistry of this series of diamagnetic ‘Werner’ complexes. Our interpretation is based upon two parameters, the donation of electron density to the metal and the steric perturbation required for coordination. The stereochemistry of uns-cis(Co(2,2,3-tet)Val)++ is assigned based upon the carbon 13 NMR spectrum of the complex.