A simple and efficient electrospinning technique is employed for the preparation of high aspect ratio semiconducting p-type copper(II) oxide (CuO) nanofibers. Characterization studies including X-ray diffraction (XRD) and scanning electron microscopy (SEM) are employed to analyze the crystal structure and morphology of electrospun CuO nanofibers. The results of XRD and SEM confirm that the nanofibers are made of copper oxide in the form of interconnected nanograins. The 12 g sample with nanograin morphology and large specific surface areas providing the highest responses to 250 ppm ethanol, 250 ppm hydrogen and 2500 ppm liquefied petroleum gas (LPG) of 32.38%, 57.01% and 21.63%, respectively. The effect of salt concentration of copper(II) nitrate on gas sensing performance was investigated. The 12 g-device shows the best response to ethanol and LPG meanwhile the 6 g-device shows the best response to hydrogen. The devices show a good selectivity to hydrogen at both working temperatures of 350 and 400 degrees C. The best device shows a percentage response of 170% to 1000 ppm hydrogen at 250 degrees C.