We report a 68-year-old Japanese man with end-stage renal failure requiring hemodialysis and chronic disseminated intravascular coagulation (DIC) related to thrombosis in an aortic aneurysm. He had undergone graft replacement for the dissection of the ascending and descending thoracic aorta in 1990 and 2002, respectively. Computed tomography disclosed an aneurysm with thrombosis in the residual aorta adjacent to the graft anastomosis. DIC was diagnosed based on elevation of serum fibrinogen degradation products while his activated partial thromboplastin time, prothrombin time and fibrinogen level were normal. In 2008, hemodialysis was initiated for end-stage renal failure. Dialysis was performed without administration of an anticoagulant because his activated clotting time (ACT) was prolonged to 150-180 s. Thereafter, stable hemodialysis continued without clotting in the dialysis circuit until 2013. If monitoring of ACT can be done, hemodialysis without anticoagulation may be a therapeutic option in such patients.