To investigate disseminated intravascular coagulation (DIC) after valve replacement, we studied DIC score in 80 patients with combined cardiac valvular disease. Thirty-three patients with (TR group) and 47 patients without (control group) tricuspid regurgitation were compared. 1) TR group, that included patients with severe cases, showed a significantly longer operative time and greater bleeding volume (p less than 0.01). 2) The DIC score was significantly higher in TR group. Administration of gabexate mesilate to patients with DIC improved their platelet counts. These results indicate that patients with combined cardiac valvular disease with tricuspid regurgitation have a hemorrhagic tendency and are subject to DIC. Administration of gabexate mesilate is useful for DIC.