Robots have progressively become more and more pervasive in our everyday lives, for example they help us on some activities like cleaning, working and also entertaining. Furthermore, they can help us to communicate in different languages, by automatic translation, text to speech translation, etc. The focus of this thesis is the study of using a social robot as an interpreter of sign language, specifically the Italian Sign Language (LIS). The robot considered in this work is Pepper, developed by Aldebaran. Pepper is a social robot, which means that it has sensors that forbid dangerous movements. Also, it is a humanoid robot, so it resembles the human appearance.