Esophageal cancer may induce progressive dysphagia. Insertion of a self-expandable metallic stent is widely used to relieve dysphagia. There are previous case reports that have described the use of membrane-covered stents to seal esophageal perforations. Complications of the use of an esophageal stent include bleeding, fistula formation, perforation, pain, tumor ingrowth and migration of the stent. A perforation may occur during or after the insertion of a stent from a contact ulcer due to the sharp ends of the metallic stents. We report a case of esophageal perforation after the insertion of a membrane-covered esophageal stent, which showed perforation at the middle portion of stent due to expansion of the stent. The perforation was sealed without surgical treatment or additional stent insertion. (Korean J Gastrointest Endosc 2008;36:366-370)