A wealth of research suggests that lowering the age of diagnosis of an Autism Spectrum Disorder (ASD) positively impacts an individual’s outcome across the wide range of symptoms present in ASD. Recent work using eye-tracking to look at the visual fixation patterns of infants at high risk for ASD in comparison with their typically developing peers indicates that infants subsequently diagnosed with ASD appear to have different visual fixation patterns from typically developing infants, even in the first two years of life, and that an infant’s level of fixation on the eyes of others can predict diagnosis. A preliminary finding suggests that infants increase their visual fixations on the mouth, peaking at approximately 16 months of age—a point in development that is known to be highly relevant for the process of language acquisition. As we know that delayed language acquisition is a hallmark of ASD, greater understanding of the importance of social-visual engagement for language development will be important in better characterizing the developmental trajectory in ASD. The current project aims to understand the developmental relevance of a change in visual fixation at this moment in development, and to contextualize it within other processes important to language-, communicative- and social-development that co-occur at this age in both typical development and ASD. Further research will examine the relevance of this increased mouth-fixation for the acquisition of language in typically developing infants and in infants with ASD, and with a long-term goal of the development of new ways to improve language abilities in infant and toddlers with ASD.