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 opening disabilities during the Activities of Daily Living (ADLs). In addition, the device, able to exert suitable forces on the hand, can be used during the rehabilitative sessions to implement specific tasks useful to restore the dexterity of the user’s hand. The validating and testing phase, conducted in collaboration with the Don Carlo Gnocchi Foundation, showed satisfying results both in terms of portability and wearability which are fundamental requirements for assistance during the Activities of Daily Living (ADLs) and for rehabilitation of people with hand impairments.