Myeloid sarcoma is a rare extramedullary tumour consisting of immature myeloid cells. It can arise at any anatomical location and often develops in the bowel. This report describes a case of severe acute disseminated intravascular coagulation (DIC) with multi-organ failure occurring in a 57-year-old man with chronic myelomonocytic leukaemia during bowel resection for newly diagnosed adenocarcinoma of the sigmoid colon. Histopa thology however revealed a differentiating myeloid sarcoma encompassing a well-differentiated adenocarcinoma. This is the first documented case of acute DIC to be triggered following surgical manipulation of myeloid sarcoma.