Chemical deposition of ultrafine gold and palladium particles into poly(3,4-ethylenedioxythiophene) matrix has yielded the metal-containing polymer composites. Their structure has been studied as affected by duration of reduced polymer immersion into the metal salts solution, and by concentration of the latter. Morphology features of the composite films (size and concentration of metal particles) have been elucidated by scanning and transmission electron microscopy. The mixed clusters have been formed predominantly in the course of preparation of bimetal composite films via sequential deposition of gold and palladium; the isolated palladium clusters nucleate slower due to the gold-palladium alloys formation. Longer deposition of the metals leads to increase in the nanoparticles size and their concentration in the composite. Properties of the prepared materials have been demonstrated using the model electrochemical reactions.