Thirty-eight patients with the diagnosis of postoperative epiduro-arachnoiditis are reported upon. All had had previous surgery for disc herniation, and the diagnosis of epiduro-arachnoiditis was confirmed at repeat surgery. Massive epidural scarring with no coexistent pathologic condition was found in every patient, and adhesive arachnoiditis was noted in three. The common clinical presentation consisted of low-back pain and sciatica, and radicular pain was usually a continuation or a recurrence of the preoperative sciatic pain. Neurologic deficits were mild, and no patients with the classic picture of adhesive arachnoiditis were found. Myelographic patterns did not disclose any correlation with the clinical symptoms. Five myelograms were normal, while six others simulated a recurrent disc herniation. The results of scar excision were good in 13 patients, fair in eight, and a failure in 17.