A new type of three-dimensional ZnO superstructures, a flower-like structure assembled by nanorods and nanosheets, was prepared via a one-pot solution approach in the absence of any templates or organic additives. Each nanorod of ZnO superstructures, with amorphous nanosheets piling up one on the other, was single crystalline and grew along the [0 0 0 1] direction. The room-temperature photoluminescence spectrum showed ultraviolet emission around 398 nm and a diverse visible emission peaks. A possible growth mechanism was proposed. (C) 2009 Elsevier B.V. All rights reserved.