The valence shell excitation spectra for P(CH 3) 3, PCl 3, PF 3, OPCl 3 and PF 5 have been obtained using electron energy loss Spectroscopy. The spectra were obtained using an impact energy of 2500 eV and a zero degree scattering angle. The spectra are tentatively assigned and interpreted with the aid of the inner shell excitation spectra and ionization potentials from photoelectron Spectroscopy. The HOMO orbital of PF 5 is confirmed as the 2e'' orbital.