Numb chin syndrome (NCS) is a rare but important clinical symptom and sign. It describes a condition presenting as anaesthesia or paraesthesia over the chin, which is usually unilateral. The condition manifests spontaneously with no history of trauma, infection or obvious odontogenic cause. NCS is a clinically important finding as it may be the primary manifestation of Multiple Sclerosis (MS) or sign of systemic malignancy. We present a case of a 58-year-old gentleman who was referred to a regional oral and maxillofacial unit with a three-month history of sudden onset unilateral numbness of the chin. No odontogenic cause could be found and subsequent CT/PET scan from the cerebellum to the upper thighs revealed evidence of widespread metastatic disease. The patient died five weeks after his initial presentation. We discuss the importance of this clinical symptom, the likely mechanism of disease and offer differential diagnoses. Additionally, we recommend that patients presenting to their general dental practitioner with a numb chin be urgently investigated for a potentially undiagnosed malignancy or MS and be referred to their local oral and maxillofacial unit as an urgent 'target' referral.