Disseminated intravascular coagulation (DIC) is a confusing disorder from both the diagnostic and therapeutic standpoints. Confusion and controversy stem from the facts that many unrelated diseases can trigger DIC, that there is a lack of uniformity in clinical manifestations and a lack of consensus in the appropriate laboratory diagnosis, and that no agreement exists about specific therapeutic methods. Recommendations for and evaluation of treatment regimens becomes even more difficult because (a) often morbidity and survival are more dependent on the specific cause of DIC and (b) none of the generally used specific therapies, including heparin, antithrombin concentrate, and protein C concentrate, have been subjected to objective prospective randomized trials.One intent of this review is to provide specific and objective guidelines and criteria for the clinical diagnosis, laboratory diagnosis, and assessment of severity of DIC and, most important, to provide an objective system to assess efficacy of any given specific therapy, free from influences of the underlying disease (1). This approach allows for objective decisions regarding diagnosis, treatment, and response to therapy in individual patients. These guidelines also provide objective criteria for prospective randomized trials to assess the safety and efficacy of a specific therapeutic agent for DIC, apart from the morbidity and mortality associated with the underlying disease(s) that induced the DIC process. In developing objective criteria, the rationale for each is briefly presented, including a general review of the etiology, pathophysiology, clinical and laboratory diagnosis, and successful treatment of DIC.