Fourteen subjects with spinal cord pathology were studied with 10 MHz linear array or 5 MHz mechanical sector ultrasound scanners. Twelve patients were studied intraoperatively. The examinations were rapid, aiding the surgeon at the time of exploration. Sonography defined cysts, outlined the extent of neoplasia and aided in the localization of bone fragments. Guidance for placement of syringo -subarachnoid shunts reduced the amount of surgical manipulation. Four patients were examined postoperatively through laminectomy defects, three confirming adequate position and function of shunts and in one case demonstrating tumor recurrence.