The dewetting behavior of polystyrene (PS) films immersed in nonsolvent, ethylene glycol, was investigated at temperatures above the glass transition temperature on planar interfaces and on the walls of cylindrical nanopores where the interfacial interactions were varied. PS nanostructures with different shaped end-caps were produced when the PS nanotubes, confined within the cylindrical nanopores of an anodic aluminum oxide (AAO) membrane, were immersed in ethylene glycol, at 130 degrees C. This system provides an easy approach for fabricating polymer nanostructures with different shapes that can be used to develop unique confined morphologies for the block copolymers. Poly(styrene-b-1,4-butadiene) (PS-b-PBD) nanospheres and hemispherically capped nanorods were produced having controlled size with different morphologies within the nanostructures.