This Special Issue on linguistic and cognitive development in children with autism spectrum disorder (ASD) arose from the 42nd Boston University Conference on Language Development (BUCLD) (2017), when Jeannette Schaeffer, Stephanie Durrleman, and Inge-Marie Eigsti organized a symposium on this topic. It shows that the study of language development in ASD provides a unique perspective on the associations between the development of syntax, pragmatics, intelligence, theory of mind, and working memory. In addition, it emphasizes the importance of studying children with ASD across the spectrum and across research groups. Such research serves to address an important question in (typical) language acquisition--whether the acquisition of pragmatics and/or syntax requires general intelligence, working memory, phonological memory, and theory of mind, or vice versa.