Heterostructured metal-semiconductor Zn-ZnO core-shell nanobelts and nanotubes have been synthesized. The core is a belt-shaped Zn single crystal, and the shell is an epitaxially grown ZnO layer of similar to5 nm in thickness. The composite nanobelt grows along [2 (1) over bar(1) over bar0], its top/bottom being +/-(0001), and side surfaces +/-(01 (1) over bar0). The Zn core is a single crystal, and the ZnO shell has an epitaxial orientation relationship with the core. The metal-based nanobelts have a distinct morphology from the nanowires reported in the literature. A growth mechanism is proposed on the basis of growth kinetics and thermodynamics. Sublimation of the Zn core results in the formation ZnO nanotubes.