OBJECT In a retrospective study in cadavers, the authors investigated the anatomical parameters between the convex and concave side in lumbar scoliosis for microsurgical discectomy and the decompression of spinal stenosis. Microsurgical intervention is the gold standard for lumbar herniotomy or the decompression of the spinal stenosis. However, the risk for complications during these procedures is higher due to the anatomical variations caused by the scoliosis. METHODS In 4 adult cadaveric scoliotic lumbar spines, the authors studied the anatomical relationship between important structures for performance of microsurgical discectomy or decompression, such as the dural sac, spinal nerve roots, and adjacent anatomical structures. They measured the following distances and compared these findings with those acquired using conventional radiographs in daily practice: nerve root outlet-ganglion center, nerve shoulder-superior disc, nerve shoulder-pedicle, nerve axilla-pedicle, nerve axilla-lower pedicle, ganglion center-pedicle, ganglion center-lower pedicle, and nerve root angle. RESULTS The mean distance of nerve root outlet-ganglion center, nerve shoulder-superior disc, nerve shoulder-pedicle, nerve axilla-pedicle, and ganglion center-pedicle was significantly different between the convex and concave side (all p < 0.05), in contrast to the results of nerve axilla-lower pedicle and ganglion center-lower pedicle, which both related to the pedicle of the lower segment (difference not significant). CONCLUSIONS For the first time, information on the anatomical variations between convex and concave sides in scoliotic lumbar spines is described, supported by comparisons with radiographic examinations. These results confirm a topographic anatomical discrepancy. This knowledge can be used in daily perioperative practice for patients undergoing microsurgical decompression.