The compounds [Ni(Ur)(6)][I-3](2). 2Ur (I) and [Co(Ur)(6)][I-3](2). 2Ur (II) are synthesized and characterized by X-ray crystallography. The crystals are isostructural, monoclinic, space group C2, Z = 4; a = 14.128(4) and 14.163(5) Angstrom, b = 11.495(4) and 11.519(3) Angstrom, c = 21.835(7) and 21.834(7) Angstrom, beta = 94.66(2)degrees and 94.88(3)degrees, V = 3534.3(2) and 3549.3(2) Angstrom(3), rho(calcd) = 2.44 and 2.43 g/cm(3) for I and II, respectively. In the crystal, the layers of diiodoiodate stacks oriented along the y axis alternate with the layers formed by similarly oriented columns of urea complexes and outer-sphere urea molecules.