A-61-year-old man presented with abdominal pain and periumbilical mass. He had no known history of toxic exposure or radiation therapy. The CT scan showed a 6 cm sized mass in the right paracolic gutter, which was filled with hematoma and air bubbles. Small bowel studies demonstrated the presence of an external compressive intraperitoneal lesion in the RLQ area. Explorative laparotomy revealed a soft tissue mass with 5 cm in diameter in the right paracolic gutter, which was resected and diagnosed as abscess with granulation tissue. Forty days later, he returned to the hospital because of anemia, dizziness, and abdominal distension. Laparotomy revealed widely disseminated malignant neoplasm in the abdomen, with multiple metastatic nodules in the ileal wall, liver, and mesenteric lymph nodes. Pathologic examination showed multifocal angiosarcomas composed of solid sheets of spindle or epithelioid cells with rudimentary lumen formation. The tumor cells were strongly positive for the CD31, CD34, and vimentin, whereas cytokeratin and epithelial membrane antigen (EMA) were negative. The review of the abscess at first operation revealed foreign body associated angiosarcoma, which showed same immunohistochemical results as small bowel angiosarcoma. We present here a patient in whom a diagnosis of multifocal angiosarcoma was set after occurrence of disseminated angiosarcoma and concurrent hemoperitoneum.