Nanofibers and nanotubes based on polymers offer a broad range of applications in areas such as photonics, sensorics, catalysis or medicine and pharmacy. A set of preparation techniques which allow to introduce simultaneous specific functions into such nanoobjects has been developed recently. These include electrospinning and co-electrospinning of nanofibers as well as template methods utilizing eletrospun nanofibers or porous substrates. These techniques yield infinitively long nanofibers and nanotubes with well defined aspect ratios respectively with diameters down to a few ten nanometers. These nanofibers and nanotubes can be functionalised, among others by using biodegradable materials or via the incorporation of nanoparticles or precursor molecules, in such a way that applications for tissue engineering, for catalysis, photonics and sensorics become available. Copyright (c) 2005 John Wiley N Sons, Ltd.