The photoluminescence emission of ZnO nanowires was modified by means of plasma etching, inducing a strong increase in the Near Band Edge emission (NBE) in the UV region (3.26 eV). In contrast, annealing treatment at 600 °C quenched the NBE peak. This opens the possibility to modify the emission properties of ZnO nanowires by means of surface treatment, and is of great importance in view of the application of ZnO as an emitting material. ZnO nanowires were prepared by the vapour phase growth technique in a tubular furnace. Morphological and structural characterization was carried out by scanning and transmission electron microscopy, showing no modifications to the morphology and crystalline arrangements after plasma etching. The nanowires are single crystalline with a high aspect ratio and diameters in the 50–100 nm range. The optical properties of the ZnO nanowires were studied by …