Nonionic contrast media are reported to cause serious adverse reactions less often than ionic contrast media. However, we treated an otherwise healthy woman with a left ureteral stone in whom disseminated intravascular coagulation developed due to intravenous administration of the nonionic contrast medium iohexol. We discuss the clinical course and possible causes of disseminated intravascular coagulation. Our case emphasizes that nonionic contrast media are not free from serious adverse reactions although the incidence seems extremely low.