Main pulmonary artery aneurysms are a rare entity with few available published data. As reported in the literature, operative treatment is commonly recommended but the relation between the size of the aneurysm, its localization, and the risk of rupture is not as well defined as for aortic aneurysms. Proximal lesions that involve the main branches of the pulmonary artery are usually apparent on chest radiographs and must be taken into consideration in the differential diagnosis of mediastinal masses. An early diagnosis allows timely surgical treatment. We report an unusual case of a main pulmonary artery aneurysm presenting with persistent non-productive cough and provide a review of the pertinent published data.