This article describes the synthesis and the electrochemical properties of a redox polymer, having a polyindole backbone and a viologen subunit, derived from the oxidative electropolymerization of N-methyl-N＇-(3-indol-1-yl-propyl)-4,4＇-bipyridinium (In-V-Me2+). Fairly stable films of poly(In-V-Me2+) were obtained on Pt and Au electrodes from acetonitrile containing Et4NClO4 as supporting electrolyte. The best films were grown on Au at potentials where electrodissolution of Au substrate occurs simultaneously with the electropolymerization. Poly(In-V-Me2+) films show interesting electrochemical properties in acetonitrile and water which stem from the behaviour of the pendant viologen redox centres. The redox reactions of the monomer have also been studied. The indole viologen shows the usual behaviour of viologen compounds both in aqueous solutions and in acetonitrile. In aqueous solutions, In-V-Me2+ forms on mercury monolayers of radical cations deposited at underpotentials with parallel and vertical orientation on the electrode surface.