Objective: From January 2000 to December 2009 (Institute of Pathology and Legal Medicine, Paolo Giaccone -Palermo) 57 autopsies were performed on 37 males and 20 females who died of a massive PTE. Method: Systematic autopsy. Results: Saddle pulmonary thrombosis in 33 cases, in 24 isolated in both the main pulmonary arteries. In all cases the transverse heart diameter was 1,5-2 cm superior to the longitudinal one, the interventricular septum became rectilinear with a right ventricular dilation. The coronary artery anatomy was: critical stenosis through fibroatheromatous plaque of the dominant right coronary artery (RCA, 2), non dominant left coronary artery (LCA, 3); non critical stenosis of RCA (14), LCA (8); absence of stenosis (30). Histological ventricular examination showed hypoxic-ischaemic and/or reperfusion and overload lesions. In all cases, the lungs showed plurifocal occlusive thrombosis of intramural pulmonary arterial (IPA) vessels associated with adjacent infarctual necrosis (49); acute partially haemorrhagic basal oedema (35) and desquamative macrophagic alveolitis (28). Conclusion: In all cases of massive PTE the thrombosis of IPA vessels associated with an adjacent infarction (86 %) is constant. This suggests that death is nearly always preceded or triggered by one or more episodes (clinically silent or with non specific symptoms) of thromboembolism of IPA vessels.