The <0001>‐oriented ZnO vertical nanowires (vnws) have been prepared by electrochemical growth for the electric charge of 0.3, 0.7, and 1.5 Ccm−2 on a <0001>‐Ga:ZnO/soda‐lime glass substrate in an simple aqueous 0.8 mmol L−1 zinc nitrate hydrate solution. All the ZnO‐vnws emitted strong ultraviolet light that originated from the recombination of a bound exciton and weak visible light due to native defects. The best performance regarding the intensity ratio and ultraviolet light intensity was obtained for the ZnO‐vnws prepared for 0.7 Ccm−2, and the performance changed depending on the electric charge. The ZnO‐vnws also showed the best scintillator performance with the luminous efficiency of 8.3% and spatial resolution of 4 μm, and the scintillator performance was closely related to the light‐guiding effects originating from the nanowire dimension in addition to the photoluminescence characteristic.