Extensive lower limb paresis developed in three patients with terminal cancer following internal iliac (hypogastric) artery embolization. This procedure was carried out for control of hemorrhage in two of the patients and for reduction of the bulk of metastatic tumor in another. The embolic materials used resulted in extensive obliteration of small and large vessels of the posterior and anterior divisions of the internal iliac artery. The paresis is attributed to the resulting ischemia of the sciatic and femoral nerves; previous radiotherapy may also have been a contributing factor. To reduce the incidence of paralysis, identification of the bleeding vessels and selective embolization are recommended. If this cannot be achieved, and the catheter lies in the main stem, it is recommended that the emboli should not be smaller than Gelfoam pledgets (1 X 1 X 10 mm) to preserve the peripheral circulation and lessen the risk of complication.