In this case report, we describe a case of adult-onset bulbar ptosis in a patient with Joubert syndrome. Joubert syndrome is a rare neurodevelopmental disorder with malformations in cerebellum and brainstem. Many ocular abnormalities have been noted in Joubert syndrome, but the association of this syndrome with adult-onset ptosis has not been described to date. This 24-year-old Joubert patient developed a cerebrospinal fluid cyst in her midbrain. She had signs of bilateral third nerve palsy and abducens palsy in the left eye. The bilateral central third nerve palsy causing functional blindness secondary to severe bilateral levator palsy was treated successfully with silicone sling frontalis suspension, as the seventh nerve nucleus was not involved.