The evaluation of patients with recurrent symptoms after lumbar disc surgery, is a difficult diagnostic problem. The causes of failure may include recurrent disc herniation, postoperative scarring, arachnoiditis, spinal stenosis, infection and mechanical instability. The most common causes are recurrent herniation and postoperative scarring; the routine x-ray and myelographic differentiation between them is difficult or impossible. High resolution CT has shown some results in the evaluation of the postoperative patients. It requires some knowledge of CT findings of "normal" pictures of the physiologic healing and scarring after disc surgery. We scanned 30 asymptomatic operated patients and 30 patients with recurrent sciatic nerve pain after disc surgery. From our observations result that it is quite impossible to distinguish "normal" scar from asymptomatic fibrosis. The degree and type of fibrosis are not related to recurrent symptoms.