We report on an uncommon type of complex dumbbell schwannoma involving the thoracolumbar region, which was successfully managed with unilateral hemilaminectomy using a modified posterior approach. A 19-year-old male patient presented with one-year history of low back pain radiating to the lower limbs, limping of two month-history, and hesitancy of micturition of 15-day duration. Clinically, a diagnosis of conus-cauda lesion was suspected. Findings of the X-ray and magnetic resonance imaging of the dorsolumbar spine were suggestive of a complex dumbbell schwannoma, extending from the lower part of the T11 level to the upper part of the L1 vertebrae left to the spinal cord, with extension through the intervertebral foramina to the paraspinal region on the left side. A modified posterior approach with unilateral laminectomy was used for complete removal of the tumor. The histological diagnosis was schwannoma. The patient had minimal pain postoperatively, he was mobilized on the third day without the need for any external support. At one year follow-up, he had normal motor and sensory functions in the lower limbs.