Recent studies on the growth of ZnO nanostructures and their optical properties were reviewed. Using different methods, a variety of ZnO nanostructures, including quantum dots nanotowers, nanotubes, nanorods, nanowires, and nanosheets, displaying zero, one, and two dimensions, have been synthesized. The growth of ZnO low-dimensional nanostructures has been demonstrated. Their optical properties have been studied by means of room-temperature photoluminescence spectra, low-temperature photoluminescence spectra, temperature-dependent photoluminescence spectra, and pressure-dependent photoluminescence spectra. The optical properties can be adjusted by the surface features of ZnO low-dimensional nanostructures. The strong exciton emission has been observed in some nanostructures, showing promising potential in nanodevice applications.