A simple and effective strategy for immobilizing enzymes covalently onto a solid porous support for catalysis is described. A polymerized high internal phase emulation (polyHIPE) was employed to achieve the process. N-Hydroxysuccinimide esters were introduced into the highly porous monolithic support for covalent coupling with the lysine residues. It was observed that the morphology of polyHIPE materials is highly suitable for immobilizing enzymes such as CAL-B, which allowing retention of a specific enzymatic activity. The covalent immobilization of the enzyme via grafting to N-hydroxysuccinimide ester moieties on the surface of the support material leads to stable levels of enzymatic activity with successive uses of the immobilized biocatalysts. Combining the polyHIPE morphology and the covalent grafting of the enzyme to the support material allows the release of immobilized biocatalysts with high and stable levels of specific activity.