The orotatotriethanolaminecopper(II) monohydrate, [Cu(C5H2N2O4)(C6H15NO3)] . H2O, has been synthesized and characterized with physico-chemical methods (IR and UV-Vis spectroscopy, magnetic susceptibility, conductivity and thermoanalytical measurements) and X-ray diffraction. The structure derived from physico-chemical methods is consistent with that of the X-ray diffraction. The compound crystallizes in the monoclinic system, space group P21/n, with a 8.6282(12), b = 16.9919(18), c = 10.6985(15) Angstrom, beta = 110.08(3)degrees, V = 1473.1(3) Angstrom(3), Z = 4. The copper atom is chelated by the deprotonated nitrogen pyrimidine atom and by the carboxylate oxygen atom of the orotate dianion ligand, and by the nitrogen and oxygen atoms of the triethanolamine ligand. The title compound has a distorted octahedral coordination geometry.