Prosthetic graft infection after arch replacement surgery is a serious complication that is often resistant to antibiotics. However, graft replacement is difficult and is very invasive. We performed anterior small thoracotomy drainage and intermittent lavage in 2 patients. First, the prosthetic graft was approached via a left third intercostal thoracotomy. After the ablation of infected tissues and cleansing with saline, drains were placed both proximally and distally to the vascular graft. An irrigation withdrawal drain was then implanted in the left thoracic cavity. After surgery, diluted povidone iodine solution, pyoktanin solution, and saline were used for pleural lavage. Case 1 : An 82-year-old man underwent arch replacement for a ruptured aortic arch aneurysm in November 2005. He suffered from high-grade fever from March 2008 and was referred to our hospital from another hospital with a diagnosis of vascular graft infection. A small anterior thoracotomy and drainage were performed on April 9. Pleural lavage with povidone iodine solution was performed 9 days after surgery, then was performed with saline from days 10-13 after surgery. The patient was discharged on postoperative day 30. Case 2 : A 58-year-old man complained of high-grade fever from March 16, 2009. He had undergone arch replacement for an aortic arch aneurysm in 1997. He consulted a physician and was referred to our hospital with a diagnosis of vascular graft infection. Methicillin-sensitive Staphylococcus aureus (MSSA) was identified by blood culture. A small anterior thoracotomy and drainage were performed on March 24. Immediately after surgery pleural lavage was performed with pyoktanin blue solution changing to povidone iodine on postoperative day 10. Pleural lavage was continued until day 34, and the patient was discharged on postoperative day 64. In both cases, drainage and pleural lavage with antibiotic solutions improved the patients' general condition. The infections have not recurred since discharge. Small anterior thoracotomy for graft infection after arch replacement, in addition to being minimally invasive, can avoid the need for a second median sternotomy, and can provide an adequate view of the full length of the arch prosthetic graft.