Shape Memory Alloys (SMAs) are innovative materials whose potential as actuators is being investigated in different fields because of their smart properties. Indeed, this material can recover a predefined shape if subjected to an appropriate thermomechanical process. The purpose of this thesis is to develop a novel hand exoskeleton actuated by SMA springs for the rehabilitation of patients affected by post-stroke hemiparesis. In the first part of the work the actual state of the art is analysed in order to identify the most suitable solutions for implementing the SMA actuation on an exoskeleton device. Afterwards, the exoskeleton is completely designed from the point of view of the mechanical structure, the electronic circuit, and the control system.