A 46-year-old woman presented with multiple purpuric skin rashes together with splenomegaly and thrombocytopenia. The resected spleen weighed 720 gm, and contained multiple, discrete, dark red, bulging nodules throughout the entire splenic parenchyma. Microscopically, the nodules revealed various range of endothelial cell proliferation which included cavernous vasculature, anastomosing vascular channels, papillary intravascular growth and solid pattern. Intrasinusoidal sequestration of platelets along with extramedullary hematopoiesis was present in the neoplastic vascular spacws. Neither exposure to thorotrast nor vinyl chloride was nonfirmed. Ultrastructurally, the tumor cells demonstrated a row of pinocytotic vesicles, occasional intercellular junctional structures, and the paucity/absence of filamentous structures or Weibel-Palade bodies supports origin of sinus lining type cells. After splenectomy, the thrombocyte count returned to normal. We conclude this is the first case of primary splenic angiosarcoma with Kasabach-Merritt syndrome in Korean literature.