We report a patient with nonoperatively treated acute cauda equina compression arising from an epidural clot that developed after decompressive surgery for lumbar canal stenosis. A 43-year-old woman underwent lumbar laminotomy, and was symptom-free for 3 hours; but this was followed by paresis. Postoperative myelography showed obstruction of the contrast column at the level of the laminotomy; this was relieved by hyperflexion of the lumbar spine. With sustained hyperflexion of the lumbar spine, all neurologic deficits were completely resolved within 5 days. Lumbar lordosis may be present when a patient lies in the supine position on a flat bed with the hips and knees extended; this may exacerbate dural constriction caused by an epidural clot following posterior lumbar spinal surgery.