Zinc oxide (ZnO) has been regarded as one of the most promising candidate for efficient UV light emitted devices owing to its unique optical properties, such as direct wide band-gap and a large exciton binding energy. In many optoelectronical applications, reducing the size of the semiconductor down to nanometer scale is necessary. However, in ZnO nanostructures the UV emission can be drastically weakened owing to high surface-to-volume ratio, crystal imperfections, or unintentional defects. These factors induce competitive processes to the nearband-edge (NBE) excitonic recombination in the UV region, including defect-related radiative recombination, resulted in the emission in the visible part of the spectrum, or other quenching processes, resulted in dissipation of excitation energy in the form of non-radiative recombination. Therefore, for future applications a strategy is needed to limit the quenching processes and to optimize the NBE emission of the ZnO nanomaterials. In this review article, the most effective approaches to achieve this goal are summarized and discussed.