Large benign goiter with a cervical and intrathoracic retrotracheal location is uncommon, but troublesome, since it affects the upper mediastinum and usually causes dyspnea, dysphagia or vascular obstruction; on the other hand, a large mediastinal cyst of thyroid origin complicated by a massive, spontaneous hemorrhage is an exceptional event, implicating vital prognosis through an acute tracheal compression. A 45-year-old-man presented all these complications of a previously neglected nodular-cystic goiter, causing an acute respiratory distress. An emergency diagnosis and consequent surgery, in delayed urgency, were performed. This case is presented because of its rarity. Its clinic management is discussed, in the framework of the existing literature.