Communication: A new route for the electrosynthesis of sexithiophene (6T) films with well-ordered structure is described. Applications of oligothiophenes in organic electronic devices-to which 6T is well suited owing to its attractive charge-transport properties-necessitate a well-defined structural order. The formation of an inclusion complex of terthiophene (3T) in the host hydroxypropyl-P-cyclodextrin in an aqueous medium is demonstrated and also that the subsequent electropolymerization leads essentially to 6T. It is shown that use of the P-cyclodextrin induces an ordering effect.