Pseudoaneurysm of the Ascending Aorta (PAA) is an extremely rare complication and is associated with high mortality despite timely surgical treatment. An 80-year-old male patient with multiple comorbidities and a history of previous cardiac surgery, presented mild dyspnea and oppressive chest pain of a subacute course. The angiotomography confirmed an anterior and retrosternal mediastinal mass compatible with a PAA. The surgical strategy consisted of open repair of the defect by median sternotomy with prior establishment of Extracorporeal Circulation with femoral cannulation. The patient presented a favorable postoperative evolution and was discharged with an indication for periodic follow-up by outpatient consultation.