Angiosarcoma is a very rare malignant tumor of endothelial cell origin. We experienced a case of angiosarcoma presented with massive pleural effusion, which was considered as a metastasis from right kidney. A 44-year-old male patient was admitted due to dyspnea for one month. He had a history of transient hematuria 3 months before admission, which disappeared spontaneously. Chest roentgenography showed total haziness in left hemithorax with multiple nodular shadows in right lung. Abdominal ultrasonogram showed a single heterogeneous hyperechoic mass, measuring about $7.3{ imes}7.1{ imes}6.5cm$ in size in the upper and mid-pole of the right kidney, involving renal sinus. Computed tomography of the chest revealed highly enhanced multiple pulmonary and subpleural nodules with loculated pleurisy. In bronchoscopic finding, a fungating, hypervascular tumor mass was noticed at the orifice of anterior basal segment of left lower lung after removal of tenaceous mucus. Pleural and bronchoscopic biopsies showed findings of angiosarcoma confirmed by immunochemical stains with factor VIII related antigen(+), laminin(+) and vimentin(+), and by characteristic electronmicroscopic findings. Massive pleural effusion was controlled with several times of pleurodesis in both pleural spaces.