Poly(3,4-ethylenedioxythiophene) conducting polymer films doped with Prussian Blue (PB, iron (III) hexacyanoferrate (II)) has been prepared by a two steps method. In a first step, the PEDOT coating was electrogenerated in the presence of ferricyanide ions. Then, the modified electrode was cycled in aqueous solution containing Fe3+ ions. The in-situ formation of PB inside the PEDOT matrix has been demonstrated by using cyclic voltammetry. The electrochemical oxidation of dopamine at the modified electrode has been studied in phosphate buffer aqueous solution. The composite coating showed a high electrocatalytic effect towards the dopamine oxidation in the presence of ascorbic acid. Linear dependence of the anodic peak current from differential pulse voltammetry over the dopamine concentration ranging from 4×10 -5 to 1×10-3 M was obtained.