Numb chin syndrome is a rare clinical manifestation, characterized by focal sensory loss and paresthesia of the chin. It is more often associated with cancer than with benign disorders, and can be the first manifestation of a cancer. A 60-year-old man presented with focal numbness of right chin and gingiva for 10 days. Chest computed tomography showed a 3 cm sized mass on the distal left main-stem bronchus. Squamous cell carcinoma was diagnosed on bronchoscopic biopsy. However, bony metastasis of mandible was not evident on reontgenogram, CT scan, bone scintigram and positron emission tomography. Despite the chemotherapy with three cycles of paclitaxel and cisplatinum, the cancer was progressed and pain on the right chin was developed 4 months .later. Bone scintigram showed multiple bony metastasis including mandible. Here we report this case with a brief review of the appropriate literature.