Precise localization of an intestinal arteriovenous malformation is essential for the complete resection of the lesion. Identification at operation can be difficult, and intraoperative angiography is not without complications. Blood flow within the small vessels of the bowel wall can be easily detected by Doppler ultrasonography, and arterial flow can be distinguished from venous flow. Intraoperative use of the Doppler ultrasound technique localized an AYM in the small intestine. Distinctive flow signals were present over the intestinal AVM which allowed it to be easily differentiated from adjacent normal intestine. Confirmation was secured by measuring the Po2 of blood aspirated from the vein draining the involved segment and comparing it to the Po2, from a vein draining an adjacent segment.