The design of an aid for the hand function based on exoskeleton technologies for patients who have lost or injured hand skills, e.g. because of neuromuscular or aging diseases, is one of the most influential challenge in modern robotics to assure them an independent and healthy life. This research activity is focused on the design and development of a low-cost Hand Exoskeleton System (HES) for supporting patients affected by hand disabilities during the Activities of Daily Living (ADLs). The device can be also used during the rehabilitative sessions to better recovery the dexterity of the user’s hand. This paper presents a compact design concept for a portable hand exoskeleton. This prototype has been developed thanks to the collaboration between the Department of Industrial Engineering (DIEF) of the University of Florence, and the Rehabilitation Engineering Laboratory of the ETH, Z¨ urich, during the eNTERFACE16 Workshop, hosted by the University of Twente.