We performed first-principles calculations to study the energetics, geometric and electronic properties of zinc sulfide (ZnS) nanostructures. ZnS nanowires (ZnSNWs), nanotubes (ZnSNTs) and nanosheets (ZnSNSs) were considered. Both ZnSNWs and ZnSNTs modeled using hexagonal prisms with the atomic arrangement displaying the characters of wurtzite crystal are more stable than the single-walled ZnS nanotubes presented in previous literature. The energy evolution of ZnSNWs and ZnSNTs as a function of tube diameter and wall thickness was calculated and explained using a simple model. The comparison between the energetics and electronic structures of these ZnS nanostructures was also addressed.