Combining the versatility of the electrospinning technique and the hydrothermal growth of nanostructures enabled the fabrication of TiO2/ZnO composite nanostructures. XRD, FESEM, TEM and EDX analysis confirmed the growth of ZnO nanosheets with a diameter of about 500 nm on the surface of TiO2 nanofibers. Gas sensing properties of the sensors fabricated from the as-prepared TiO2/ZnO, TiO2 and ZnO were systematically investigated. The TiO2/ZnO sensor exhibits a response of 15.7 to 100 ppm of ethanol at 280 °C, which is much better than pure TiO2 and ZnO. The enhanced sensing performance to ethanol is mainly attributed to the formation of heterojunctions between TiO2 and ZnO, which leads to the interfacial transport of excess carriers.