Pulmonary artery dissection is a rare and fatal disease. Diagnosis is mainly made during autopsy because most patients die suddenly due to pulmonary artery dissection in the pericardium resulting in pericardial tamponade. The optimum management is not clearly defined because of the paucity of cases in the literature. We describe the case of an 81-year-old man, affected by rheumatoid arthritis and with history of aortic valve replacement surgery, who attended an emergency department for non-specific symptoms, started complaining of chest pain rapidly deteriorated into cardiac shock. Computed tomography scan, performed on suspicion of an acute aortic pathology and/or a pulmonary embolism, allowed the identification of pulmonary artery dissection associated with aorto-pulmonary fistula. Despite early diagnosis in the emergency department, the outcome was unfortunately fatal.