BACKGROUND: Disordered expressive prosody is a widely reported characteristic of individuals with autism. Despite this, it has received little attention in the literature and the few studies that have addressed it have not described its relationship to other aspects of communication. AIMS: To determine the nature and relationship of expressive and receptive language, phonology, pragmatics, and non-verbal ability in school-aged children with high-functioning autism and to determine how prosody relates to these abilities and which aspects of prosody are most affected. METHODS & PROCEDURES: A total of 31 children with high-functioning autism and 72 typically developing children matched for verbal mental age completed a battery of speech, language, and non-verbal assessments and a procedure for assessing receptive and expressive prosody. OUTCOMES & RESULTS: Language skills varied, but the majority of children with high-functioning autism had deficits in at least one aspect of language with expressive language most severely impaired. All of the children with high-functioning autism had difficulty with at least one aspect of prosody and prosodic ability correlated highly with expressive and receptive language. The children with high-functioning autism showed significantly poorer prosodic skills than the control group, even after adjusting for verbal mental age. CONCLUSIONS: Investigating prosody and its relationship to language in autism is clinically important because expressive prosodic disorders add an additional social and communication barrier for these children and problems are often life-long even when other areas of language improve. Furthermore, a receptive prosodic impairment may have implications not only for understanding the many functions of prosody but also for general language comprehension.