Variable energy valence and inner valence photoelectron spectra have been recorded between 21 and 170 eV using He I, He II, and synchrotron radiation for the bis(eta(3)-allyl) metal complexes M(eta(3)-C3H5)(2) (M = Ni, Pd, and Pt). MS-X alpha-SW ground state and transition state calculations have been performed on the trans and cis structures. Photoionization cross sections have also been calculated for the valence ionizations of the three trans isomers, using both the Gelius and MS-X alpha-SW methods. The theoretical branching ratios (sigma(i)/Sigma sigma) from both theoretical methods have been compared with the observed branching ratios between 21 and 170 eV. The orbital energies and orbitals characters for the cis complexes compared with the trans complexes indicate that our spectra are predominantly due to the trans complexes. For trans-Ni(eta(3)-C3H5)(2), our assignment (from the high-resolution He I and He II spectra and the good agreement between theoretical and observed branching ratios between 21 and 90 eV) gives the following orbital ordering : 13a(g), 12a(g) < 6b(g), 7a(u) < 11a(g) < 5b(g) < 11b(g) < 10a(g). This ordering is very different from that proposed from all previous experimental and theoretical assignments. In particular, the low binding energy peak at 7.64 eV is assigned to two orbitals, 13a(g) and 12a(g), of mainly Ni 3d character rather than the ligand 7a(u) orbital. The 7a(u) orbital contributes mainly to the second band at 8.1 eV. Apart from this discrepancy, our assignment of the MO ordering agrees with our X alpha-SW energies. In contrast, the low binding energy peaks in the Pd and Pt analogues at 7.64 and 7.91 eV, respectively, arise from the ligand 8a(u) and 12a(u) orbitals as proposed earlier. : 13a(g), 12a(g) < 6b(g), 7a(u) < 11a(g) < 5b(g) < 11b(g) < 10a(g). This ordering is very different from that proposed from all previous experimental and theoretical assignments. In particular, the low binding energy peak at 7.64 eV is assigned to two orbitals, 13a(g) and 12a(g), of mainly Ni 3d character rather than the ligand 7a(u) orbital. The 7a(u) orbital contributes mainly to the second band at 8.1 eV. Apart from this discrepancy, our assignment of the MO ordering agrees with our X alpha-SW energies. In contrast, the low binding energy peaks in the Pd and Pt analogues at 7.64 and 7.91 eV, respectively, arise from the ligand 8a(u) and 12a(u) orbitals as proposed earlier.