Chylothorax is reported as a postoperative complication, mainly in the field of thoracic surgery, but there are only 14 reports in the field of spinal surgery. A 64-year-old woman underwent spinal fusion surgery by the anterior and posterior approach for her scoliosis. She developed leg edema and right pleural effusion 2 months after the surgery. Laboratory findings showed decreased total protein and albumin levels in serum. The color of the thoracentesis sample was pinkish white, and the Triglyceride level in the pleural effusion was high. So, her leg edema was found to be associated with malnutrition and the pleural effusion was caused by chylothorax. The point of leakage from the lymph duct was confirmed in the right thoracic cavity of the slice that corresponded to that with the screw at Th11 by lymphatic scintigraphy. Her symptoms did not improve by diet restriction and lipidol lymphography, but her pleural effusion and albumin levels improved by the administration of octreotide. In the clinical course, serum albumin levels appeared to show an inverse correlation with the amount of pleural effusion, so it was thought that her serum albumin level decreased owing to leakage of protein, including albumin, into the thoracic cavity via the injured thoracic duct. We concluded that the chylothorax was owing to complications of the surgery. Although reports of chylothorax occurring as a complication of spinal fusion surgery are rare, when prolonged hypoalbuminemia or unilateral pleural effusion is observed, chylothorax should be considered as a differential diagnosis.