In this study, cadmium sulfide (CdS), polypyrrole (PPy) nanowires, and their heterojunctions have been electrochemically synthesized. Morphology of the nanowires has been investigated by scanning electron microscopy. Energy dispersed X-ray, X-ray diffraction, UV-Vis, and FTIR analyses have been used to confirm structure of both CdS and PPy nanowires. For the first time with this study, CdS/PPy nanowire heterojunctions have been integrated into photoelectrochemical (PEC) cells. It has been also demonstrated that PEC performance of the nanowires was strongly function of production conditions, such as deposition time and voltage. The maximum power conversion efficiency of the CdS nanowires obtained in this study was 1.36%. Moreover, efficiencies of the CdS/PPy nanowires have been reached to 5.00%, which makes them very favorable for PEC applications.