Ionic fragmentation following photoionization from the shallowest d core orbital in organometallic molecules with a group II-V element (ZnMe{sub 2}, GaMe{sub 3}, GeMe{sub 4}, SnMe{sub 4}, PbMe{sub 4}, and BiMe{sub 3} (Me = CH{sub 3})) has been studied in the vapor phase. The threshold electron spectra and photoionization efficiency curves of these molecules are presented and discussed. Photoionization from the (n -1)d core orbitals (n = 4 for ZnMe{sub 2}, GaMe{sub 3}, and GeMe{sub 4}, n = 5 for SnMe{sub 4}, and n = 6 for PbMe{sub 4} and BiMe{sub 3}) is identified in the threshold electron spectra of these molecules.