Abstract: A method for producing nanocapsules with cross-linked protein-based walls, comprising preparing emulsions of said proteins and crosslinking these with a crosslinking agent having reactive groups which react with the reactive groups of said proteins, particularly acylatable groups, to cause an interfaced crosslinking reaction between the proteins and the crosslinking agent, and thereby form capsules with walls based on the proteins crosslinked by the crosslinking agent. A fine emulsion of said proteins is prepared by adjusting the surface tension of the various liquid phases. Biocompatible and biodegradable nanocapsules having improved controlled release are thereby obtained.