We report on a previously undocumented complication of a trocar-free thoracostomy tube--delayed perforation of a normal esophagus. The complication presented clinically with fever and copious enteric drainage four days after thoracostomy tube insertion. Diagnosis was established by a contrast study of the esophagus. Retrospectively, the postinsertion chest radiograph showed the offending thoracostomy tube tip impinging on the posterior mediastinum, displacing an indwelling nasogastric tube. Early recognition and repositioning of the thoracostomy tube is the key in preventing this rare but serious complication.