Composites with conducting polymers (ICPs) as a matrix were electrodeposited on anodes of platinum or carbon black filled polypropylene from a stirred electrolyte with dispersed particulate materials (concentration c E) such as copper phthalocyanine or carbon black (CB). The solvent (H2O or CH3CN) contained the monomer (pyrrole or bithiophene) and the supporting electrolyte, 0.1 M LiClO4. The concentration c C in the composite increases in proportion to log c E, starting from a threshold value c E,O. c C-Values of 2–60% are found, depending on the nature of the dispersed material; c E,0 varies widely, from 1 mg dm−3 to 1 g dm−3. A codeposition mechanism could be derived, consisting of two steps: I. Temkin type strong adsorption of the particle and II. charge transfer. II was treated as an activated, potential dependent process. In case of the polypyrrole/CB-composite c C decreases with increasing BET-surface. This is rationalized in terms of a synchronous charge of the electrochemical double layer capacitance of the CB particles. PPy as a matrix is superior over polybithiophene, were oligomers are dissolving. High insertion rates (c C) are obtained in comparison to other systems.