Empyema developed in a 62-year-old man after right pneumonectomy for lung cancer. According to the Clagett procedure, an open window thoracostomy was made with two ribs removed. After 5 weeks, primary closure of the fenestra was attempted. Because the fenestra was too large to be primarily closed, a rectus abdominis musculocutaneous flap was successfully transposed to cover the chest wall. There was no evidence of recurrence of empyema during 11 months' observation after closure. In patients with a large fenestra and with little tissue left for closure, the rectus abdominis musculocutaneous flap could be of great help in completing the Clagett procedure.