Spontaneous haemothorax is a rare and often lethal complication of neurofibromatosis. Two kinds of vascular involvement are described: 1) stenotic or aneurysmatic modifications of large intrathoracic vessels, mainly treated with endovascular techniques; 2) dysplastic alterations in highly vascularized mesenchymal tumors. We describe a rare case of massive intrathoracic haemorrhage due to an upper mediastinic neurofibroma, successfully controlled with recombinant activated factor VII associated with surgical treatment.