In this report, polypyrrole nanowires have been successfully deposited on interdigitated transducers through template-free electropolymerization. The nanowires were 40-90 nm in diameter according to scanning electron microscopy analysis, and some of them were bridging the insulating gaps between gold electrodes. An X-ray photoelectron spectroscopy study has been conducted to determine the chemical composition of the synthesized nanomaterial. The developed sensors were tested toward five concentrations of hydrogen gas at room temperature, and their sensitivities were compared. Due to the very high surface area of the deposited sensitive films, these sensors provided faster response compared to other polypyrrole-based gas sensors. Moreover, it is shown that the sensors' sensitivities are related to the amount of the deposited PPY nanowires.