The present study deals with "P magic angle spinning solid state nuclear magnetic resonance (NMR) investigations on various substituted ethylmercaptocyclotetraphosphazenes. Through analyses of spinning side band intensities the isotropic chemical shifts, the principal values of the magnetic shielding tensor, the span and skew could be determined and interpreted with regard to the different substituents of the compounds. In addition, the crystal structural parameters of N4P4C14(SC2H5)4 were determined by X-ray structural analysis. Using these parameters 3'P NMR chemical shifts and the principal values of the magnetic shielding tensor were calculated by the individual gauged of localized orbitals (IGLO) method.