Undoped and Li-doped ZnO nanowires were grown on Si(111) substrates using a thermal evaporation method. Undoped and Li-doped ZnO nanoparticles, which were prepared using a sol–gel method, were used as material sources to grow the undoped and Li-doped ZnO nanowires, respectively. X-ray diffraction patterns clearly indicated hexagonal structures for all of the products. The nanowires were completely straight, with non-aligned arrays, and were tapered. Field emission Auger spectrometer indicated lithium element in the nanowires structures. Photoluminescence (PL) studies showed lower optical properties for the Li-doped ZnO nanowires compared to the undoped ZnO nanowires. Furthermore, the UV peak of the Li-doped ZnO nanowires was red-shifted compared to the undoped ZnO nanowires. Two probe method results proved that the Li-doped ZnO nanowires exhibited p-type properties.