ZnO has long been considered as a promising candidate material for diluted magnetic semiconductors, owing to its theoretically predicted and experimentally observed above-room-temperature ferromagnetism and long spin-coherence time. In this brief perspective, recent progress in ZnO diluted magnetic semiconductors is reviewed with particular focus on three topics: (1) spin coherence in ZnO; (2) free-carrier type and concentration-dependent magnetic properties in ZnO; and (3) ferromagnetism in undoped and non-transition-metal-doped ZnO. Finally, current status and possible potential direction of research on ZnO diluted magnetic semiconductors are summarized in the concluding remarks.