Acute mediastinitis is almost always secondary to some other condition, and most cases are due to esophageal perforation. Although acute mediastinitis from odontogenic infection is extremely rare in the era of antibiotic drugs, some more fulminant odontogenic infections can produce complications including airway obstruction, necrotizing fascitis and extension of the infection to thorax. Irrespective of the changing incidence of etiologic factors, unless the pathophysiology of acute mediastinitis and its causes are understood and the conditions promptly recognized and properly treated, the result may be prolonged illness and even death. We experienced a case of odontogenic infection followed by acute mediastinitis and present review of literature.