||Recent research on personal robots shows that robots are increasingly being used as partners that collaborate with people and support them in everyday tasks. Robot companions, for example, are envisioned to play an important role in several applications, such as providing assistance for the elderly at home, serving as tutors for children by enriching their learning experiences, acting as therapeutic tools for people with autism or as game buddies for entertainment purposes. These applications require robots to be endowed with social abilities in order to behave in a safe, socially acceptable manner and adapt to humans in an intelligent way in challenging, complex natural environments. Social skills include the ability to perceive users, understand their social signals and states, account for the context in which the interaction takes place, and respond in an appropriate manner. This talk will provide an overview of my work on socially intelligent robots and review some of the challenges that need to be overcome in order develop robots capable of engaging in long-term natural interactions with humans.