Background and Aim : Language disorders are one of the most prominent features seen in autistic children. The present study intends to investigate some linguistic features of speech in Persian-speaking children with autism in comparison with their typically developing age mates.

Materials and Methods : By recording the speech of 20 autistic girls and boys who were seven to eleven years old, phonetic, phonologic, morphologic and syntactic features of their speech were compared with those of their typically developing age-mates. The SPSS (18) and Exact Fischer Test were used to analyze the collected data.

Results : The results showed that consonant deletion, substitution of phonemes, using stress on inappropriate syllable, atypical intonation, incorrect use of tense, incorrect use or not using prepositions, problems in making the nouns plural and not using complex sentences were significantly different in children with autism and typically developing children (p<0.05), while epenthesis, metathesis, violating subject-verb agreement, having difficulty with making the verbs negative, and using demonstratives were not significantly different (p>0.05).

Conclusion : Children with autism had more problems in phonetic, phonologic, morphologic and syntactic features of speech in comparison with their typically developing age-mates. Therefore, withappropriate treatment programs, these problems could be reduced.

Key Words : Autistic children, Typically developing children, Phonetic and phonologic features, Morphologic and syntactic features