A reproducible method is presented for selecting patients with low-back pain and sciatica for lumbar discectomy based on specific objective criteria in four categories: neurologic signs, sciatic tension signs, personality factors (MMPI scores), and lumbar myelography. Operative findings for 50 consecutive cases selected using this method revealed complete nucleus pulposus herniation in 43 cases. This contrasts with complete herniation in only 5 of 26 patients undergoing lumbar discectomy before the method was employed. This objective preoperative evaluation method reduced negative disc explorations and improved early surgical results. We recommend its use for patients being considered for elective lumbar discectomy.