Bronchopulmonar intralobar sequestrations receive their arterial blood supply through anomalous arteries from the systemic circulation. Usually the lumen of the aberrant artery can be oversized, but it is unusual to find a true arterial aneurysm. Here, we report a case of a 40-year-old woman with this unusual evolution. Because of the potential risk of rupture, she was treated with a lobectomy associated with a resection of the aneurysm.