Objective: To assess the value of the diagnosis of overt disseminated intravascular coagulation (DIC) according to the International Society on Thrombosis and Haemostasis (ISTH) criteria and that of the parameters included in the ISTH score for overt DIC in predicting day 28 mortality in intensive care patients. Also, to assess the value of the components of the score in the diagnosis of overt DIC. Design and setting: Retrospective clinical study in a university hospital intensive care unit. Patients and participants: 494 consecutive patients admitted in the ICU between January 2002 and October 2003. Measurements and results: Clinical and laboratory data, including hemostatic parameters, were collected from computerized databases and patient files. Altogether 19% (95/494) of the patients fulfilled the criteria for overt DIC. Their day 28 mortality rate was higher than that of patients without overt DIC (40% vs. 16%). The lowest platelet count (area under curve, AUC, 0.910), highest plasma D-dimer (AUC 0.846), lowest antithrombin (AUC 0.823), and Owren-type prothrombin time activity (AUC 0.797) discriminated well the patients with and without overt DIC, whereas plasma fibrinogen (AUC 0.690) had poor discriminative power. No patient with the diagnosis of overt DIC had decreased plasma fibrinogen. Day-1 SOFA and APACHE II score, the first CRP measurement, and the lowest antithrombin were independent predictors of day 28 mortality. Conclusions: The diagnosis of overt DIC was not an independent predictor of day 28 mortality. In ICU patients plasma antithrombin seems a promising candidate in the panel of indicators for overt DIC whereas the value of plasma fibrinogen is in doubt.