Nanofibers are defined as fibres with diameters on the order of 100 nanometers. They can be produced by interfacial polymerisation and electrospinning. Contrastly, carbon nanofibers are graphitised fibres produced by catalystic synthesis. Nanofibers are included in garments, insulation and in energy storage. They are also used in medical applications, which include drug and gene delivery, artificial blood vessels, artificial organs and medical facemasks. This book presents new research in this dynamic field.