A case of Ludwig's angina dissected along deep cervical fascial planes into the mediastinum caused a virulent mediastinitis and abscess. Computed tomography precisely delineated the extent of the infection. Incomplete débridement resulted in a residual abscess and persistent systemic sepsis that culminated in the patient's death. Aggressive antibiotic treatment of the orofacial cellulitis along with complete mediastinal drainage are recommended for optimal outcome.