Transition metal oxide clusters and their derivatives o4er an unmatched variety of structural motifs that are potential building blocks for the design and development of extended solids. In view of the proven applications of these clusters in catalysis, molecular recognition, environmental decontamination, clinical and analytical processes, materials science, nanotechnology, and medicine, their usage as building blocks promises the development of new materials whose properties could be rationalized in terms of their constituents. Although the technique of assembling appropriate transition metal oxide clusters to generate new solids is still underdeveloped, recent progress made in this direction is promising. During our ongoing research program focused on this aspect, we have been able to prepare and characterize a series of novel framework materials, composed of well de5ned vanadium oxide clusters +V 18 O 42 (XO 4 ), (X β«Ψβ¬ V, S, Cl). We have also prepared three-dimensional composite solids by incorporating organic ligands into the transition metal oxide framework. Some of the results of this work are reviewed with reference to the synthesis, structure, and physicochemical properties of the newly prepared extended solids.