Purpose: To determine the relation between the location of disc herniation and the direction of sciatic scoliotic list and to clarify the mechanism of sciatic scoliotic list. Materials and Methods: Forty-five patients with lumbar disc herniation and scoliotic list were studied prospectively. Direction of scoliotic list, preoperative and postoperative Cobb's angle, displacement of the first lumbar vertebra from center sacral line were measured. Location, side and degree of disc herniation were observed during operation. Results: There was no statistically significant relation between the location or degree of nerve root compression and the direction or degree of sciatic scoliosis. There was no statistically significant relation between the location or degree of nerve root compression and displacement of the first lumbar spine from center sacral line. There was significant relation between the side of disc herniation and the direction of sciatic scoliosis. Most of the sciatic scoliotic list was disappeared after surgical decompression. Conclusion: The direction of sciatic scoliosis was not related to the location of nerve root compression but related to the side of disc herniation. The herniated disc might be reduced in size by stretching or inward bulging at the convex side of the scoliosis.