Therapeutic effects of FOY on DIC were investigated in 74 patients with DIC, including 32 with leukemia, 15 with carcinoma, 10 with infection and 17 with other disorders. The diagnosis of DIC and its severity were based on the criteria determined by the DIC research group of Japan Ministry of Health and Welfare. FOY was administered by a continuous infusion for more than 5days at 1-2mg/kg/h. Some patients were treated with the combination of FOY and heparin (6,000-10,000U). Platelet counts after the treatment were significantly increased than those at initial diagnosis with the exception of patients with leukemia. The normalizations of serum FDP and serum fibrinogen concentration were observed. Hemorrhagic symptoms were improved in 52% cases and the diagnostic score decreased after the treatment. No side effects but one (mild leukopenia) were found during the administration of FOY. These results indicate that FOY is useful and safe for the treatment of DIC.