D-dimer test is used as a diagnosis test for acute disseminated intravascular coagulation (DIC). This study was undertaken to find out its sensitivity and specificity in the diagnosis of acute DIC and its role in diagnosis of sub-clinical DIC, as there is limited data available on the subject. Of the 29 patients of clinically acute DIC, all had positive D-dimer test, and markedly prolonged PT, APTT and TT were seen in 24 (83%) of these patients. D-dimer test was found to be highly specific but less sensitive for the diagnosis of acute DIC. Of the 29 patients predisposed to sub-clinical DIC. D-dimer was positive is 26 (90%) patients and PT, APTT and TT were mildly prolonged in 11 patients. It is suggested that D-dimer positivity for the diagnoses of sub-clinical DIC need to be considered with caution and to be supplemented by other coagulation test including serial follow up with d-dimer and coagulation tests.