Photoproduction of π0 mesons off targets of 6Li, 12C, 28Si, 40Ca, natural Cd, and natural Pb was studied using a bremsstrahlung beam with endpoint energies of 140, 145, 150, and 155 MeV. Photoproduction from a liquid hydrogen target was employed as a normalization. The measured yields were found to be in disagreement with published theoretical cross sections for 6Li(γ, π0)6Li and also in disagreement with a simple schematic model which assumed only coherent contributions from the M1+ multipole. The schematic model, however, did approximately predict the relative magnitudes of the yield curves for the energy range 14-20 MeV over threshold. NUCLEAR REACTIONS 6Li, 12C, 28Si, 40Ca, Cd, Pb, (γ, π0) Eγ=140-155 MeV; measured σ test of reaction model.