The discovery and development of periodic porous materials of well-defined pore geometry with precise and easily controllable pore shape and size is of great importance in many areas of modern science and technology. In this regard, mesoporous and hierarchical (micro-meso-macro) molecular sieves including zeolite-like metal-organic framework structures (MOFs) are the new generation ordered porous solids, analogous to conventional microporous (zeolitic) materials, with high surface area, large pore opening and huge pore volumes. On the one hand, the unique flexibility of these materials, in terms of synthetic conditions, pore size tuning, high surface area, large internal hydroxyl groups, framework substitution, etc., have created new avenues not only in catalysis but also in the areas of advanced energy materials and environmental pollution control strategies. On the other hand, the preparation and characterization of high quality materials with well-defined pore characteristics is of paramount importance for many applications in areas including nanomaterials, catalysis, adsorption and separation. In designing such materials, several characteristics of pore structure may be addressed, which include their shape, size, pore interconnectivity, etc. Likewise, traditional preparation methods of supported catalyst systems are neither efficient in generating/dispersing uniform sized clusters nor chemically inert towards the guest molecules. Nevertheless, the confinement of nanoclusters/nanofilaments/enzymes in the cavities/voids/pores of nanostructured matrices is attracting much attention as a way to stabilize highly dispersed materials in the form of atoms, clusters, colloids or filaments, and prevent their coalescence into to larger, ill-defined aggregates. In this context, self-assembly of nanoparticles into ordered pore structures, i.e., encapsulation of the nanosized materials in zeolitic-pores, is considered as one of the promising options. Therefore, in this presentation, the recent progress on the development of numerous nanoscale materials and their applications in catalysis will be discussed.