 Autism Spectrum Disorders ASD is characterized by a pattern of persistent deficits in communication and abnormal behaviors i.e., repetitive and restrictive. Previous research has shown promising results for the use of social robots to develop social skills in ASD children. However, most of the research is based on case studies and single case experiments. Rigorous clinical data comparing robot--enhanced therapy with standard therapy is needed to establish the efficacy of this innovative intervention. The present study is an equivalence randomised clinical trial which plans to include children with a diagnosis of ASD between 3 to 6 years old. Eligible children are randomly allocated in one of two groups: 1 standard therapy, derived from applied behavior analysis ABA and 2 a robot--enhanced intervention in which the same treatment is delivered by a semi--autonomous robotic mediator agent the robot acts as a mediator while the therapist is supervising the session. Both interventions are delivered over 8 bi-weekly sessions of about 45 minutes each. The present study will provide some of the first rigorous data regarding the efficacy of robot--enhanced therapy delivered by an intelligent robotic agent which require less direct input from an operator to deliver the intervention, as compared to previous research. If the results demonstrate the equivalence of the two interventions, this could open the door for the dissemination of evidence--based interventions for ASD children through the use of robotic agents. 