Intra-abdominal "angiosarcomatosis" report of two cases after pelvic irradiation. Angiosarcomas account for only 1% to 2% of all soft tissue sarcomas with the most common site of origin being skin and subcutaneous tissue particularly on the face and scalp of elderly patients. These neoplasms rarely arise in the small or large bowel with presentation as diffuse abdominal "angiosarcomatosis." Two patients are reported who were treated with adjuvant pelvic irradiation for gynecologic malignancies (squamous cell carcinoma of the cervix and adenocarcinoma of the endometrium) in whom diffuse abdominal angiosarcoma of intestinal origin developed 7 and 18 years later. Both patients were treated with standard megavoltage irradiation. The clinical course was rapid in both cases with death due to intra-abdominal hemorrhage and bowel obstruction. The pertinent literature relating to the association between radiation therapy and subsequent development of angiosarcomas of soft tissues and other sites is briefly reviewed. 