We describe a young snowboarder suffering from dyspnea, chest pain and dysphagia following a blunt chest injury. These symptoms were caused by an accident-related hemorrhage within a preexisting lymphangioma of the right posterior mediastinum. At the same time a lymphangioma of the left anterior mediastinum was found. The lymphangioma of the posterior mediastinum was resected through a right posterolateral thoracotomy after thoracoscopy had demonstrated that a complete resection could not be performed on this way. The lymphangioma of the left side was resected 4 month later by a left-sided hemiclamshell approach due to its size and localisation. Complications arising from mediastinal lymphangioma are described as compression, infection, spontaneous bleeding, rupture and chylothorax. This is the first description of a posttraumatic, symptomatic hemorrhage within a mediastinal lymphangioma.