The laboratory tests of 38 patients in pediatric age with Disseminated Intravascular Coagulation (DIC) were retrospectively evaluated. In all patients were performed PT, aPTT, platelets count, FDP dosage and biological assay of Fibrinogen. In most of them the activity of FII, FV, FVII, FX and FVIII was assaied. According to the diagnostic criteria of FSP greater than 8 micrograms/ml, Platelets less than 150 10(9)/1 and Fibrinogen less than 150 ml/dl, in 16 patients the diagnosis of DIC was possible since first examination, while in 9 patients it became possible within 2-4 days; in 13 patients we never could diagnose DIC, although it was reasonably present, since the criteria above mentioned were never simultaneously satisfied. Looking back in our experience, we confirm that the platelets count and the quantitation of plasmatic Fibrin Degradation Products (FDP) are the most useful tests for the diagnosis of full blown DIC, and that the biological assay of plasmatic fibrinogen helps to follow the disorder. A low level of FVIII:C seems to be a forecast of failure. None of the other test performed give any useful information for diagnosis when it is not possible with the above mentioned tests.