Neurofibromatosis 1 (NF1) is a common autosomal dominant disorder that causes several systemic diseases. Many studies have reported that NF1 is associated with intrathoracic meningoceles and scoliosis. The incidence of vertebral artery dissection is estimated to be 1-1.5 per 100,000 population. We experienced an autopsy case of massive intrathoracic hemorrhage due to spontaneous vertebral artery dissection in a patient with NF1, who had intrathoracic spinal meningoceles and scoliosis. A 47-year-old man was found dead at his home in the morning. He had a history of NF1 including numerous cutaneous neurofibromas and hyperpigmented macules, scoliosis, and deformity of the leg. The autopsy revealed the dissection and rupture of the left vertebral artery, and a pseudocyst that had formed due to arterial leakage on the wall of the meningocele on the left side. The pseudocyst had eventually ruptured and leaked blood, resulting in a massive hemothorax on the left side. Thus, it was revealed that the patient had suffered from NF1-associated intrathoracic meningoceles and scoliosis, and we concluded that the cause of his death was a massive hemothorax on the left side, caused by the dissection and rupture of the left vertebral artery.