Reconfigurable nanowire transistors merge the electrical properties of unipolar n-and p-type FETs into a single type of device with identic technology, geometry and composition. These four-terminal nanowire transistors employ an electric signal to dynamically program unipolar n-or p-type behavior. More than reducing the technological complexity, they open up the possibility of dynamically programming the functions of circuits at the device level, i.e. enabling a fine-grain reconfiguration of complex functions. We will review different reconfigurable concepts, analyze the transport properties and finally assess their maturity for building circuits. (C) 2014 Elsevier Ltd. All rights reserved.