Tetanus is fatal neurological disease caused by Clostridium tetani on contaminated wound that is characterised by muscle spasm, muscle pain, and autonomic dysfuction. C. tetani exist on contaminated wound frequently that developed clinical tetanus under low oxygen condition. Tetanus have four symptomatic form: generalized, localized, cephalic, and neonatal. The incubation period is about 7 days and mortality is high. The commonest presenting symptom is trismus and other is stiffness of neck and back(opisthotonos), muscle spasm, dysphagia, facial pain, risus sardonicus. Trismus is primary presenting symptom in 50~75% of the cases and this have high possibility of initial visit to dental office. This case report of a patient who visit in our department with trismus as chief complaint.