Abstract Objective Analysis of the effectiveness of early Parental Coaching in the Autism Spectrum Disorder. Method Randomized, controlled and blinded clinical trial to analyze parent-child interaction videos. Results The sample consisted of 18 children being followed up at the Autism Outpatient Clinic of a Neuropediatric Center in southern Brazil diagnosed with Autism Spectrum Disorder, between 29 and 42 months of age, randomly allocated to two groups: the Study Group (SG; n = 9), which received Parental Coaching performed by a professional certified by the Early Start Denver Model; and the Control Group (CG; n = 9), which was in a routine follow-up, without treatment and training of parents by a trained professional. The parents of the SG were willing to attend weekly meetings and to apply the instructional techniques at home with their children. It took 12 weeks and an average of 2 h per meeting. Conclusions The learning rate for comprehensive development skills in the Early Start Denver Model checklist, such as receptive communication, expressive communication, social capacity, imitation, cognition, games, fine motor skills, gross motor skills, behavior, and personal independence was significantly higher in the SG, as well as the strategies and the quality of interaction between parents and children. Thus, Parental Coaching presents as a possibility of early intervention in children with Autism Spectrum Disorder.