Introduction: Marcus Gunn Syndrome, also known as Jaw Wink Syndrome or trigemino-oculomotor synkinesis, was first reported in 1883. It typically presents at birth with unilateral ptosis and eyelid elevation on jaw opening. Pathophysiology is explained by an oculofacial synkinesis. There is an aberrant connection of the oculomotor nerve and the mandibular branch of the trigeminal nerve resulting in eyelid elevation on mouth opening. The typically congenital syndrome is exceptionally rare. It is often diagnosed in infancy with complete ophthalmic examination and ptosis evaluation. This syndrome does not often require surgical intervention but it may still have an impact in clinical management. Case description: A 32-year-old male presented in the OMFS outpatient clinic in Countess of Chester Hospital for extraction of his lower third molars. His past medical history included a known diagnosis of Marcus Gunn Syndrome but he was otherwise fit and well. He had resting ptosis of the left and elevation of the left eyelid on jaw protrusion. Results and conclusions: Third molars were removed uneventfully under local anesthesia and no further treatment was required. Literature suggests that patients with Marcus Gunn Syndrome may have an atypical oculocardiac reflex during their surgical procedure and patients are at increased risk of malignant hypothermia. In this case, the procedure was performed under local anesthesia but this condition may impact on surgical planning if general anesthesia was to be considered.