We report a high-yield synthetic method for a new type of metal nanostructure, spiky gold nanoshells, which combine the morphological characteristics of hollow metal nanoshells and nanorods. Our method utilizes block copolymer assemblies and polymer beads as templates for the growth of spiky nanoshells. Various shapes of spiky metal nanoshells were prepared in addition to spherical nanoshells by using block copolymer assemblies such as rod-like micelles, vesicles, and bilayers as templates. Furthermore, spiky gold shells encapsulating magnetic nanoparticles or quantum dots were prepared based on the ability of block copolymers to self-assemble with various types of nanoparticles and molecules. The capability to encapsulate other materials in the core, the shape tunability, and the highly structured surface of spiky nanoshells should benefit a range of imaging, sensing, and medical applications of metal nanostructures.