A 74 year-old man presenting with esophageal perforation associated with mediastinitis due to the swallowing of a fish bone is reported herein. Conservative treatment, including starvation therapy and the injection of antibiotic drugs, proved to be successful for this patient. Although the optimal treatment for esophageal perforation remains controversial, it is important to choose the appropriate strategies when treating cases of esophageal perforation with mediastinitis.