A ductal aneurysm is very rarely diagnosed in adults. We experienced 2 cases of adult ductal aneurysm. Both cases developed hoarseness and computed tomographic scanning demonstrated a typical 'triple star sign' at the aortopulmonary window level. They underwent surgical repair with successful results. During the same period, we experienced 38 operations for true thoracic aneurysm. The ductus origin was found in 5.2% of these patients. The ductal aneurysm may no longer be considered a 'rare' vascular disease with more careful diagnostic procedure.