Ludwig's angina is a threatening infection of the sublingual and submaxillary space, first described by Von Ludwig in 1836. In the preantibiotic era, mortality has exceeded fifty percent, and fatality are still reported. The supprative inflammation of this space develops from dental infection mainly and also develop from compound fracture of the mandible, traumatic laceration of the floor of the mouth, peritonsillar abscess and other systemic disease. Recently the authors experienced one case of Ludwig's angina dissected along deep cervical fascial plane into the parapharyngeal space, retropharyngeal space and anterior mediastinum. This is a report on this case with literature review.