ZnS nanostructures with different morphologies of submicrospheres, nanosheets and nanorods were synthesized by solution precipitation of thiourea with Zn(NO3)(2) in the presence of block copolymer at low temperature. The sizes and morphologies of ZnS can be controlled simply by changing the processing parameters. The results show that the ZnS submicrospheres are of 250-500 nm in diameter, nanosheets are 2.5 mu m x 5.5 mu m with an estimated thickness of 20-30 nm, and nanorods are 2-5 nm in diameter and 10-30 nm in length. Keeping the precursor system in an autoclave at 105 degrees C results in the formation of ZnS submicrospheres; ultrasonication and keeping the system at room temperature leads to the formation of ZnS nanosheets; and long-time continuous ultrasonication and keeping the system in an autoclave at 105 degrees C induces the formation of uniform ZnS nanorods. We argue that the reaction temperature and P123 may play crucial roles in the formation of three ZnS structures in this work. The morphologically controllable synthesis strategies may be extended to the shape-controlled production of nanostructures of other inorganic materials.