Diagnosis Procedure Combination (DPC) was introduced at Hirosaki University School of Medicine Hospital in June, 2003. The impact of DPC in thoracic surgery was investigated based upon the fee for service reimbursement. We retrospectively reviewed 185 cases of thoracic surgery between April 2004 and February 2005, which were reimbursed by DPC. Compared to the former payment system DPC was costlier by 6%. The DPC was high in groups which had coronary bypass surgery, valvular disease operation, aortic arch replacement, congenital heart disease radical operation and lobectomy for lung cancer except in the group that was treated conservatively for an aortic dissection case. In 16 cases DPC was less than with the former payment system. In these cases hospital stay was shorter and in the cases of long hospitalization, complications needed postoperative treatment, a dialysis case needed preoperational treatment of renal insufficiency, and other cases needed before and post operative cardiac catheter tests. Postoperative complications should be prevented, but when they are unavoidable, there is room for improvement by setting a new arm or changing basic charge of DPC.