Medical conditions and accidents can cause immobility in certain parts of the body such as the upper extremities. To help people in the rehabilitation process, various robotic devices have been designed, such as exoskeletons; however, they have limited features that did not achieve optimal performance. This article presents a systematic review of the design of hand exoskeletons applied to rehabilitation. The goal is to provide the researcher with a structured matrix of features and components for the development of a much more efficient hand exoskeleton. Different databases and specialized search engines were used because they helped in the collection of information from the different investigations from the year 2019 to 2021. Filtering and selection of the investigations were carried out, so in the end, only 33 investigations were selected. Finally, it is concluded that there is the possibility of improvement in the development of hand exoskeletons that contribute to the rehabilitation process.