The crystal structures of two new metal-cyanide clusters with record high nuclearities are reported. A direct assembly reaction involving [(Me(3)tacn)Cr(CN)(3)] (Me(3)tacn = N,N',N'-trimethyl-1,4,7-triazacyclononane), Nil(2), and KCN in aqueous solution affords [(Me-3- tacn)(12)Cr12Ni12(CN)(48)](12+). The structure of this 24-metal cluster features a cube of eight Cr-III centers linked along the edges by 12 trans-coordinated [Ni(CN)(4)](2-) units, and capped on four faces by [(Me3tacn)Cr](3+) moieties. Its metal-cyanide cage encloses a 900 Angstrom(3) cavity that is accessible through the two noncapped cube faces. A still larger cluster, [(Me(3)tacn)(14)Cr14Ni13(CN)(48)](20+), was obtained from a related reaction excluding the addition of KCN. This 27-metal species possesses a highly anisotropic geometry in which two face-centered cubic units are fused through a common Ni-II vertex.