ZnS hollow nanospheres with porous shells were successfully fabricated by a simple one-pot template-free hydrothermal route with the assistance of trolamine. The hollow nanospheres with a mean diameter of about 220 nm and the pore size of the porous shell of about 3.2 nm exhibit large BET surface areas of 129.9 m2 g21. The formation of ZnS hollow nanospheres was definitely driven by the well-known Ostwald ripening process. The morphology of the product could be controlled by adjusting the volume of trolamine in the ternary solution, which could influence the nucleation density and rate of the growing region during the initial stage of reaction. As synthesized, highly defective nanocrystalline ZnS exhibits a very strong defect-related green emission, which may pertain to the emission enhancement of the unique geometrical morphology of ZnS hollow nanospheres with a porous shell. The observed green PL emission of the wurtzite-type ZnS nanomaterials could provide an interesting application in the development of novel luminescent devices.