Polypyrrole-zinc sulfide (PPy-ZnS) and poly(3,4-ethylenedioxythiophene)-zinc sulfide (PEDOT-ZnS) composite films were synthesized and characterized. Their electrochemical behaviors were investigated. The synthesis of PPy-ZnS and PEDOT-ZnS composite films was carried out by electropolymerization of pyrrole and 3,4-ethylenedioxythiophene in the presence of ZnS nanoparticles dispersed in the electrolytic solution. The structures of the PPy-ZnS and PEDOT-ZnS composite films were characterized by the use of scanning electron microscopy, atomic force microscopy, and UV-vis spectroscopy. Cyclic voltammetry was used to determine the electrochemical behavior of the resulting materials. The Energy Dispersive X-Ray mapping (EDX mapping) method was used to detect the existence of Zn and S ions on PPy-ZnS and the Zn ion on PEDOT-ZnS composite films. A four-probe technique was used to measure the conductivity of PPy-ZnS and PEDOT-ZnS composite films along with PPy and PEDOT.