Single crystals of Ba2[(UO2)(C2O4)2(NCS)]NCS · 7H2O were prepared and studied by X-ray diffraction. The crystals are monoclinic, space group P21/c, Z = 4, a = 13.508(5) Å, b = 12.268(4) Å, c = 14.965(5) Å, β = 115.38(1)°, V = 2240.6(13) Å3. The main structural units in the crystal are the island complex species [(UO2)(C2O4)2(NCS)]3− corresponding to the crystal chemical group AB201 M1 (A = UO22+, B01 = C2O42−, M1 = NCS−) of uranyl complexes, which are united into a three-dimensional framework through electrostatic interactions and through hydrogen bonds involving oxalate and isocyanate ions and water molecules.