Postoperative rehabilitation is required for a successful outcome following total knee arthroplasty. Traditionally rehabilitative programs aim to increase range of motion, to strengthen quadriceps, to restore normal gait, and to recover independence in activities of daily living. In the last decade action observation treatment, in addition to conventional physiotherapy has been proposed as a treatment method in rehabilitative medicine. There is growing evidence of the applicability of action observation training in rehabilitative medicine, indeed it has been applied in the rehabilitation of stroke of Parkinson disease of cerebral palsy and of aphasia.