P-type CuO appears to be a good candidate for gas sensing applications. And surface morphology of this material plays a vital role in affecting its sensitivity towards various gases when analysed by Kelvin probe surface workfunction sensing scheme. We determined that CuO shows high sensitivity to carbon monoxide only in the form of nanowires. Whereas CuO thin film shows good sensitivity to NH3 and NO2 gases but nanowires do not. And ethanol sensing seems to be indifferent to surface morphology. We also noticed that both materials were insensitive to various concentrations of acetone at all operating temperatures.