This paper reviews the results of investigations into the electrochemical formation and properties of redox-active films formed from fullerenes and selected transition-metal complexes. These polymeric films are formed on the electrode surface during electroreduction of a solution containing a fullerene or a fullerene derivative and complexes of Pd(II), Pt(II), Rh(II) and Ir(I). The polymeric network is formed through covalent bonding between the transition-metal atoms (or complexes) and the fullerenes. Films containing C₆₀ exhibit electrochemical activity in the negative potential range due to the reduction of the fullerene component. In this potential range, a decrease in the film resistance is also observed. In the case of the well-studied C₆₀/Pt and C₆₀/Pd films, the polymer formation process may also be accompanied by deposition of metal nanocrystals if a high ratio of metal complex to fullerene is used during film formation. The presence of this metallic phase in the film influences its morphology, structure, and electrochemical properties. Films formed from C₆₀ with covalently bound electron-donating groups exhibit electrochemical activity in both negative and positive potential ranges. Since these systems exhibit both p- and n-doping properties, they can be called ‘double cables’. These fullerene/transition-metal films may have considerable potential for a number of applications. They can be used as charge storage materials for batteries and photovoltaic devices. The C₆₀/Pd film can be also used as an electrochemical sensor. Films of C₆₀/Pd and C₆₀/Pt containing metallic palladium or platinum particles catalyze hydrogenation of olefins and acetylenes. Laser ablation of electrochemically formed C₆₀/M and C₇₀/M films (M=Pt or Ir) results in the fragmentation and formation of hetero-fullerenes such us [C₅₉M]⁺ and [C₅₈M]^–. To cite this article: K. Winkler and A.L. Balch, C. R. Chimie 9 (2006).