Pseudoaneurysm of the pulmonary artery (PA) induced by Swan-Ganz catheter injury is an important complication with high mortality. We report a case of PA pseudoaneurysm treated by PA repair. A 52-year-old woman developing infiltrate in the right lung field in chest radiography after a second mitral valve replacement was diagnosed with PA pseudoaneurysm confirmed by contrast-enhanced computed tomography and pulmonary angiography. The cause was considered Swan-Ganz catheter injury. The patient was carefully observed because there was no evidence of bronchial hemorrhage. The perforation was closed and the cavity plicated under extracorporeal circulation to avoid delayed rupture of the pseudoaneurysm when she underwent a third mitral valve replacement.