Four cases of life threatening deep neck infection with thoracic complications were presented. Mediastinits were observed in 4 cases and purulent pleural effusion in 3 cases. The original infections were odontogenic Ludwig’s angina (2 cases); traumatic pyriform sinus with cervical esophageal perforation (1 case) and infection of upper respiratory tract (1 case). All four patients have recovered uneventfully. The history, decending routes, microbiology and management of this disease were discussed. Early recognition, immediate surgical drainage, empirical antibiotic treatment, airway management and adequate correction of exacerbating general condition are recommended.