Perigraft seromas are uncommon after surgical repair of the thoracic aorta with woven polyester grafts. A 50-year-old woman required redo sternotomy for the treatment of a perigraft seroma 6 months after total arch replacement for acute type A dissection. After removal of a jelly-like mass, a prosthetic graft was covered with fibrin glue, and the bilateral pleurae beside the graft were opened widely for drainage of effusion into the bilateral pleural cavities. Bacterial culture and laboratory and histological examination of the content confirmed the final diagnosis of perigraft seroma. No evidence of recurrence was observed 4 months after drainage.