A series of tertiary phosphine substituted alkyl- and acyltetracarbonylmanganese(I) complexes has been studied by cross-polarization and magic-angle-spinning (CP-MAS), P-31 solid-state NMR spectroscopy. All the spectra show an asymmetric sextet due to one-bond P-31-Mn-55 spin-spin coupling and second-order quadrupolar effects, transmitted by dipolar coupling between the Mn-55 and P-31 nuclei, which are not suppressed by magic-angle spinning. The chemical shift tensors, spin-spin coupling constants, dipolar coupling constants, quadrupolar coupling constants, and anisotropies in the spin-spin coupling have been determined. The shielding anisotropies of the alkyl complexes are larger than are those for the acyl complexes. The solid-state (1)J(Mn-P) spin-spin coupling constants range from 196 to 204 Hz for the alkyl compounds and from 216 to 233 Kz for the acyl complexes. The (1)J(Mn-P) values obtained from the solution Mn-55 NMR spectra for the alkyl complexes are similar to 50 Hz larger than are those obtained from the P-31 solid-state NMR studies. The nuclear quadrupole coupling constants range from 23 to 25 MHz.