A Gd-Ag coordination polymer [Gd2Ag2(pydc)(4)(H2O)(4)](n) (pydc = pyridine-2,5-dicarboxylate) with lamellar structure was prepared by the hydrothermal reaction of Gd2O3, AgNO3, H(2)pydc and H2O in a molar ratio of 1 : 4 : 5 : 3100 at 170 degrees C and characterized by single-crystal X-ray diffraction analysis.