Electro-oxidative polymerization of aniline is facilitated by modification of electrode surfaces with an inorganic polyoxometalate, namely with self-assembled monolayers of dodecamolybdophosphate, PMo12O403- and dodecatungstophosphate PW12O403-. Introduction of a protonated and therefore positively charged 1,12 diaminododecane [NH2-(CH2)(12)-NH2] adlayer can invert the interfacial charge and significantly inhibits the access of anilinium monomers. Consequently, the deposition of polyaniline with spatial selectivity is feasible, and preferential growth of the polymer on electrode surfaces modified with polyoxometalate has been observed. Microcontact printed patterns of the polyoxometalate or of 1,12 diaminododecane on top of a full polyoxometalate monolayer allows the electropolymerization of aniline to be triggered or inhibited locally. (C) 2003 The Electrochemical Society.