Pierre robin syndrome with unilateral ankylosis and obstructive sleep apnoea is uncommon. Pierre robin syndrome is characterised by a triad of micrognathia,obstructive sleep apnoea and glossoptosis. Child usually presents with hypoplastic mandible which displaces the tongue posteriorly and causes difficulty in breathing. Pierre robin syndrome is not a syndrome as such rather it is a sequence of a collection of disorders, with an abnormality presenting in other events to occur. It is usually associated with U- shaped cleft palate. It may also be associated with several other craniofacial anomalies like velocardiofacial and stickler syndrome. We hereby present a case of 18-year-old female who presented with complaints of inability to open mouth and difficulty to eat since childhood. The orthopontogram showed fusion of the left temporomandibular joint and plain computed tomography showed severe sclerosis and expansion of the left condylar process with the left temporomandibular joint's glenoid fossa flattening with irregularities and ankylosis/fusion with loss of symmetry in the skull base and smaller left hemimandible with misalignment of dentition and a pushed back tongue with a narrow airway.
