This article presents state‐of‐the art information on speech and language development and skills in infants, toddlers, children, and adolescents with Down syndrome. Research is cited in the areas of early speech and language development, receptive and expressive language, auditory and visual reception, processing and integration as they relate to language learning, semantics, syntax, morphology, pragmatics, and social interactive language. Research is also reviewed on oral motor strength and coordination, as well as oral‐motor planning as they relate to articulation, phonology, and intelligibility. Strengths and challenges, assessment, and intervention research are discussed in relation to each speech and language area. © 1996 Wiley‐Liss, Inc.