Angiosarcoma is an extremely rare sarcoma arising from oral mucosa. We report a case of angiosarcoma in the right maxillary gingiva causing excessive bleeding. The lesion exhibited typical histologic features of angiosarcoma, showing infiltrative proliferation of polygonal endothelial cells and arborizing blood vessels. Tumor cells showed expression of CD 31 and factor VIII, but no expression of CD 34 antigen. The patient expired due to severe bleeding in the oral cavity.