From recent research work, it has been found that the ZnO nanostructures have good field-emission performance. This article compares the emission characteristics of ZnO nanopins (such as I-V curve, thermal stability, and aging process) with those of carbon nanotubes. From this comparison, it can be seen that the emission characteristic of ZnO nanopins is close to that of carbon nanotubes. However, the emission performance of ZnO nanopins is much better than that of carbon nanotubes after baking at high temperature. Apart from this, the emission uniformity of ZnO cathode is quite good without an activation process. Therefore, ZnO nanopins can be used as field emitters in a field-emission-display device. (c) 2007 American Vacuum Society.