Thrombosis within the vascular system in relation to inflammation and stasis is potentially associated with poor prognosis in patients with heart failure. The aim of this study was to clarify the association between disseminated intravascular coagulation (DIC) score, a scoring system for microvascular thrombosis and multiple organ dysfunction, and outcome in hospitalized patients with acute heart failure (AHF). We retrospectively evaluated 160 AHF patients referred to a cardiac intensive care unit who had their DIC score measured according to the Japanese Association for Acute Medicine (JAAM) DIC scoring system on admission. Platelet count, prothrombin time ratio, fibrin/fibrinogen degradation products, and the criteria for systemic inflammatory response syndrome were measured. Using the JAAM DIC score, the prevalence of DIC (score ≥4) in AHF patients was 5.0% (8 of 160 patients). The risk of death for patients grouped according to the DIC score was 27.8%, 46.2%, and 87.5% for DIC scores 0–1, 2–3, and ≥4, respectively (median follow-up 460 days). In multivariate analysis adjusted for various markers of disease severity, a DIC score ≥2 was independently associated with a higher all-cause death rate (adjusted hazard ratio 2.45; P = 0.005) and a higher rate of reaching the combined endpoint of all-cause death and readmission for AHF (adjusted hazard ratio 2.10; P = 0.006) after admission for AHF. In an intensive care setting, measurement of DIC score on admission could help risk stratification in hospitalized patients with AHF.