Abstract: A process for the recovery of high purity boehmite with controlled pore size from spent hydroprocessing catalyst includes the step of treating the spent hydroprocessing catalyst composition in order to get recovery of the aluminas after extracting the valuable metals. The process permits easy and resourceful recovery of high quality boehmite from waste catalyst, which can be further used as hydroprocessing catalyst carrier having a pore structure almost identical or better than that used in heavy oil hydroprocessing catalysts. Such catalyst carrier is required to have high pore volume, macro-porosity, high strength and optimum surface area for active metal dispersion. The treating steps include process steps such as decoking, roasting, leaching, dissolving, digestion, precipitation, washing, stripping, and the like. The recovery steps include digestion, hydrothermal treatment, flocculation or precipitation, filtration, drying, calcination and the like.