Abstract
An 86‐year‐old man, diagnosed as having carcinoma of the prostate, stage D, was admitted to the hospital. Soon after admission, he developed bleeding from various sites, including intravenous puncture sites and gastrointestinal and urinary tracts. A clinical diagnosis of disseminated intravascular coagulation (DIC) was made, which was corraborated by laboratory data. A factor VIII inhibitor of 12.5 Bethesda units was also identified in the patient's plasma. Concomitant occurrence of disseminated intravascular coagulation and an acquired factor VIII inhibitor has not been reported previously.