It has been reported (I. Watanabe, K. Hong and M. F. Rubner, Langmuir, 6 (1990) 1164) that polyalkylthiophenes are not suitable for multilayer formation owing to the lack of a suitable interaction with the water surface. Therefore it seems that, in order to obtain polymers useful for the preparation of multilayers, this class of polymer should be subjected to chemical modifications that improve the polarity of the macromolecule. We have mainly modified the side chain of the polymers by introducing an oxygen atom in different positions on the alkyl side chain. This modification has the advantage that the polyenic backbone is unperturbed by the change in chemical structure. The aim of this work is to report on some data concerning the preparation and the characterization of Langmuir-Blodgett multilayers prepared with this new class of polymer.