Pulmonary artery pseudoaneurysm is an unusual complication of surgically implantable central venous port catheters. We experienced a case of a 57-year-old man with gastric malignancy, in which a port catheter had been previously implanted for chemotherapy. Because of a puncture site that was also medial for the subclavian vein, the catheter tip fractured between the first rib and the clavicle, and embolized in the left pulmonary artery, which caused a 5 x 4 cm pseudoaneurysm that mandated surgical resection with a lobectomy. The diagnostic work-up and a review of the literature are presented.