Background. The term "Kasabaha-Merit syndrome" is often used as a eponym for general description of the for coagulation disorders in different vascular lesions in both children and adults. However, subsequent studies show that for certain types of vascular tumors and vascular malformations different types of coagulopathy occur. The aim of the study is to determine which vascular anomalies are at risk for coagulopathy. Methods: 64 patients aged from 1 month to 15 years with vascular anomalies were enrolled in prospective investigation. Of the 26 patients with vascular tumors 20 have hemangiomas, including 6 liver hemangiomas, 2 have kaposhiforme hemangioendothelioma, 1 tufted angioma, and 3 PHACE syndrome. Vascular malformations have 38 patients, 15 of them have cystic lymphatic malformations, 8 have primary lymphedema, 11 have venous malformations, 2 have arteriovenous malformation, and two have CLOVES syndrome. Measurement of D-dimer levels, platelet count, and fibrinogen in blood, witсh was drawn from a peripheral vein not involved by the vascular anomalies. Results. None patients with hemangiomas had any coagulation disorders. Very low platelet count so called Kasabach-Merritt phenomenon had two patients younger than one year with rare local aggressive tumor kaposiform hemangioendothelioma. 14 year old patient with huge tufted angioma of extremities had normal platelet count. Among the 11 patients with venous malformations (VM) 6 (54.5%) had elevated D-dimer levels. Patients with multiple gastrointestinal venous malformations had very high D-dimer lever (≥4 µg/ml) associated with low fibrinogen level. Patients with large unifocal truncal VM and VM of perineum and pelvis had D-dimer levels above 1 µg/ml and normal fibrinogen level. In contrast, patients with small localized VM of limbs and children with lymphatic malformations had normal coagulations tests. Conclusions. Children with vascular anomalies have risk of coagulopathy. Very low platelet count is specific for kaposhiform hemangioendothelioma and tufted angioma and is age dependent. Elevated D-dimer level is highly specific for VMs and don’t depends of patients age only of VMs size.