This report presents a 23-year-old man with esophageal perforation, tension pneumomediastinum, and subsequent cardiorespiratory arrest. Initial resuscitation by cervical and subxiphoid mediastinotomy was ineffective. Bedside decompression of the posterior mediastinum through the esophageal hiatus of the diaphragm resulted in immediate return of a normal sinus rhythm and noncompromised mechanical ventilation. The patient made a full recovery and was discharged on day 12. Transhiatal decompression of the posterior mediastinum can be recommended for the treatment of cardiorespiratory complications in patients with tension pneumomediastinum in whom the classic cervical and subxiphoid mediastinotomies are ineffective.