Background: Treacher-Collins syndrome is a congenital craniofacial disorder with multiple anomalies. This syndrome affects the maxilla, mandible, eyes, middle and outer ears, and soft palate. Conductive hearing loss due to the deformities of the middle and external ears is prevalent. The characteristics of this syndrome include multiple and serious threats to normal communication development in children. In this study, speech and language features of a Persian speaking child with this syndrome are presented.Case: The case was an 8-year old girl with Treacher-Collins syndrome and bilateral moderate conductive hearing loss due to atretic canal. In language and speech assessments, moderate hypernasality, numerous compensatory errors and morphosyntactic deficits were observed. There were 13 phonemes that were incorrectly produced at least in one position. Besides, she used 22 types of phonological processes that were abnormal and disappear before the age of three in normal Persian speaking children.Conclusion: Moderate hearing loss, velopharyngeal incompetency, malocclusion and dental anomalies, attention deficit/hyperactivity disorder (ADHD) and environmental factors resulted in severe speech and language disorders in this case. These disorders affected her academic performance as well. Moderate hypernasality, numerous compensatory errors, and excessive and abnormal use of phonological processes were not presented as prevalent characteristics of Treacher-Collins syndrome in other resources.