The geometric, energetic, and electronic structures of zinc sulfide (ZnS) nanowires (NWs) and nanotubes (NTs) with hexagonal cross sections were explored using interatomic potential (IP) and first-principles calculations. The size-dependent surface structures, energetic evolution, and electronic properties of these nanomaterials were addressed. The formation energy of the NWs with respect to wurtzite ZnS crystal decreases monotonously with the increase in wire radius, whereas that of the multiwalled ZnS-NTs decreases with the increasing wall thickness, irrespective of the tube radius. The faceted ZnS-NTs with thick walls have energetic superiority over the cylindrical tubes built analogously to the boron nitride (BN) nanotubes. Both the ZnS-NWs and NTs are wide-band gap semiconductors with a direct band gap at Γ point. The results provide vital information for the fabrication and utilization of ZnS nanomaterials, for example, for building nanoscale optical and photonic devices.