Conductive composite films of cis-1,4-polybutadiene (PBD) with polythiophene, (PTh) were prepared electrochemicallly. Thiophene was polymerized on PBD-coated platinium electrodes. The composites with different PTh percentages showed conductivity in the order of 10(-3) (Omega cm)(-1). The characterization of the films was performed using FTIR, scanning electron microscope and differential scanning calorimetry techniques. In order to understand the dominant transport mechanism, the temperature dependence of conductivity was investigated.