Expressive prosody is thought to be disordered in autism, and this study sets out to evaluate one aspect (prosodic boundary) to investigate how naïve judges rate utterances for atypicality; whether pitch and duration measurements in those utterances differ from those of typically-developing children; and whether children with autism can use prosodic boundary in speech for linguistic distinctions. Samples were drawn from children with language-delayed high-functioning autism (LD-HFA), with Asperger's syndrome (AS), and with typical development (TD). Results showed that naïve judges perceived children with LD-HFA as sounding more atypical than those with AS, who were marginally more atypical than those with TD. Measurements suggested those with LD-HFA had wider pitch-span than those with TD. The groups did not differ on linguistic functionality, and it is possible that factors other than prosody contributed to the perception of atypicality.