Aggressive angiomyxomas are rare soft tissue tumors found mainly in the female reproductive mesenchyme and pelvis. They are low-grade sarcomas that have a propensity to recur locally. These tumors are encapsulated and have the same consistency as normal connective tissue, thus making wide excision difficult. We report a case of a large aggressive angiomyxoma in the perirectal tissues treated with preoperative angiographic embolization, causing ischemia of the tumor and, thus, improved visualization of the lesion. In addition, preoperative external beam irradiation and intraoperative electron beam radiotherapy were used to decrease the chances of local recurrence.