Pseudoaneurysm is defined as a reperfused pulsatile hematoma, encapsulated and communicated with the damaged vessel's lumen. It originates when there is a disruption of the arterial wall. Hemoptysis is a very rare sign/symptom of a thoracic aortic aneurysm or pseudoaneurysm. There is little information on hemoptysis associated with aortic aneurysm rupture, whose mechanisms are not explained by the presence of an aortopulmonary fistula. Among the hypotheses to explain this phenomenon, is the ability of the bronchial arteries to become hyperplasic and tortuous in the presence of a lesion that modifies the pulmonary architecture, being more susceptible to rupture. There are also descriptions of direct lung parenchymal injury from ruptured aneurysm. The present case illustrates that we must consider the hemoptysis as a warning sign in differential diagnosis of aortic aneurysms and pseudo aneurysms, among other causes, that it can be fatal in a short time due to massive hemorrhage.