An 83-year-old man experienced chronic disseminated intravascular coagulation (DIC) with repeated hemorrhagic episodes after undergoing chest stent-graft insertion although no obvious leaks were detectable. On an outpatient basis, intermittent administration of recombinant thrombomodulin (rTM) was started. The DIC score, which was nine prior to administration, showed rapid improvement and remained at around six 1 year after the start of rTM. No symptoms of hemorrhage were noted. Outpatient treatment with rTM was considered to be effective without impairing the patient’s quality of life.