For the first time, nanostructures of polystyrene (PS) were obtained by chemically synthesising PS within the pores of microporous and nanoporous particle track-etched membranes (PTMs). The emulsion polymerisation of styrene into nanopores with diameters ranging from 50 nm to 2 mu m is investigated. The pore size and the polymerisation time have a significant effect on the molecular weights and on the polydispersity index of PS. Thermal analyses were conducted on different PS nanostructures and the glass transition temperature was determined. The morphology of the obtained nanostructures was analysed by held-effect scanning electron microscopy (FE-SEM). Hollow PS tubules were formed because some initiator radicals were adsorbed on the pore walls. By using an initiator and a surfactant, which were both negatively charged, the polymerisation of styrene occurred at two places leading to the formation of PS tubules with PS latex particles that were present inside.