In this paper, PPy-WO3 hybrid nanocomposites with different weight percentages of WO3 nanoparticles (5-40%wt) dispersed in polypyrrole (PPy) matrix were prepared and utilized as a new sensing material for acetone detection. PPy-WO3 hybrid nanocomposite were deposited on interdigitated electrode by the electrospinning technique. WO3 nanoparticles and PPy-WO3 nanocomposites sensor were characterized by X-ray diffraction and field emission scanning electron microscopy, respectively. The presence of WO3 in PPy matrix was confirmed by EDAX. The resistance changes of different nanocomposites in exposure to acetone and methanol in three temperature (70 °C, 90 °C, and 110 °C) was tested and the results were compared with polypyrrole-based sensor. It was found that enhanced acetone sensing properties of PPy-WO3 nanocomposite films strongly influenced by the WO3 weight percentage and temperature. Comparing with PPy-based sensor, prepared PPy-WO3 hybrid nanocomposite films exhibit excellent acetone vapor sensing properties at low temperature. The detection limit of PPy-WO3 (20%) hybrid nanocomposite sensor is about 16 times better than PPy sensor and it shows fast response (< 5 s) toward acetone vapor at operating temperature of 90 °C. As a result, PPy-WO3 hybrid nanocomposite sensor can be a good candidate for high performance acetone detection.