Disseminated intravascular coagulation, although an uncommon diagnosis on a general medical service, is one of the most common, acquired disorders of coagulation. With more aggressive therapy of critically ill patients it is also a diagnosis which is increasing in frequency. Recent advances in our understanding of the underlying causes for DIC and its pathophysiology have led to the establishment of diagnostic criteria and guidelines for the management of patients. Hemorrhage and thrombosis are the major criteria for initiation of therapy, and heparin is the most efficacious approach when correction of underlying causes is inadequate. Frequent monitoring of patients on heparin therapy can improve the benefit-to-risk ratio for this disorder.