A 30-year-old woman with Von Recklinghausen's disease was admitted to our hospital because of sudden onset of dyspnea and syncope. A chest roentgenogram showed a massive right pleural effusion and insertion of an intercostal tube drained 1,600 cc of blood. A computed tomographic chest scan with contrast revealed a hyperdense mass in the right paravertebral area. At thoracotomy, retained clotted hemothorax and continued bleeding from tumor vessels was noted. The apex of the right hemithorax and the tumor location was packed. The pathologic diagnosis was ganglioneuroma and follow-up of the patient for 2 years after re-thoracotomy and removal of the packs revealed no complication and morbidity. We report this case to emphasize the importance of early recognition and prompt surgical intervention in spontaneous hemothorax associated with Von Recklinghausen's disease.