Pyridineselenolate complexes of Cd(II) and Hg(II) have been prepared by proton transfer reactions of pyridineseleno with metal carboxylates. The compounds have been characterized by NMR and IR spectroscopy and by single-crystal X-ray diffraction. The cadmium complex crystallizes in the monoclinic space group C2/c, with a = 30.163(5) angstrom, b = 7.574(1) angstrom, c = 20.862(2) angstrom, beta = 96.20(1)-degrees, V = 4738(1) A, Z = 4, and rho(calc) = 2.392 g/cm3 (Mo Ka radiation at 23-degrees-C). The crystal structure is that of a one-dimensional array of cadmium ions and two bridging pyridineselenolate ligands, with both selenium atoms and one nitrogen atom of each ligand pair binding to each metal. The mercury complex crystallizes in the space group P2(1)/n with a = 11.208(1) angstrom, b = 4.169(1) angstrom, c = 12.706(1) angstrom, beta = 100.55(1)-degrees, V = 583.7(2) angstrom, Z = 2, and rho(calc) = 2.929 g/cm3 (Mo Kalpha radiation at 23-degrees-C). The square planar mercury ions are bound to a pair of chelating pyridineselenolate ligands, with weak contacts between the mercury ion and two selenium atoms from adjacent molecules. Both compounds sublime without decomposition and decompose at higher temperatures to give solid-state MSe.