ABSTRACT Purpose: To verify the effects of the Speech-Language Intervention with Augmentative and Alternative Communication (AAC) in communicative acts in children with Autism Spectrum Disorder (ASD). Method: This is a longitudinal case-study design involving three subjects attended in a Speech-Language Pathology (SLP) Clinic School. Primary data were obtained from the observation of recorded videos of pre and post-intervention therapist assessment sessions with each child in play activities, while secondary data come from interviews with parents. The analysis was performed based on the Pragmatic Test of the Infant Language Test - ABFW, through observational recordings, aiming to identify and quantify the communicative acts. Results: It was possible to observe a 51.47% increase in the production of communicative acts in the three research subjects. In addition, it was found that there was higher quality in the acts produced, using more present verbal components and decreased acts that had non-interpersonal functions, such as gestures and vocal acts. Thus, there was an evolution in the functional language of the subjects. Conclusion: The use of Augmentative and Alternative Communication in the SLP therapy clinic is promising and effective in promoting the development of communication skills of individuals with ASD.