Novel tectocapsules were prepared by interfacial assembly and covalent cross-linking of poly(divinylbenzene-alt-maleic anhydride) microspheres at the oil-water interface. Dispersions of the anhydride-functional microspheres in a range of organic core solvents, including xylene and propyl acetate and their mixtures, were in turn suspended in a continuous aqueous phase. Addition of polyethylenimines with number average molecular weights ranging from about 200 to about 100000 to the aqueous phase led to the formation of up to 200 mum diameter tectocapsules, having walls comprised of cross-linked microspheres. The effects of microsphere loading, composition and solubility parameter of the core solvents, type of amine, and rate of amine addition on wall morphology are discussed.