Disseminated intravascular coagulation (DIC) is characterised by an imbalance between prothrombotic and antithrombotic activities. It may complicate a wide range of clinical disorders, including tissue destruction associated with surgery or trauma, serious bacterial or non-bacterial infection, malignancy and a variety of obstetric mishaps. Increased consumption/degradation and reduced production result in low levels of the most important natural inhibitor of thrombin, antithrombin. The clinical presentation of DIC is variable. Sometimes there is little obvious apart from oozing from venepuncture sites but some patients present with serious bleeding. Obstetric complications are frequently associated with clinically severe DIC. The basis of the diagnosis of DIC is an appreciation of the underlying disorders in which DIC can develop. Acute DIC is a serious complication which carries with it a high risk of mortality. It is generally accepted that the cornerstone of management of DIC is treatment of the underlying cause.