We report a remarkable enhancement in the extent of protein (lysozyme) crystallization at a wide class of oil/water interfaces. Additionally, for the case of a 1,2-dichloroethane/aqueous interface, we present initial data which show how the extent of crystallization can be further controlled via the application of a potential across the interface. These results indicate that protein crystallization can be directed at oil/water interfaces through judicious selection of the oil phase and the experimental conditions.