A 65-year-old woman who underwent transforaminal lumbar interbody fusion at L4-5 for very severe spinal stenosis combined with a hard disc and instability presented with a headache on postoperative day (POD) 3 and cerebrospinal fluid (CSF) leakage on POD 5. Follow-up lumbar spine computed tomography (CT) was performed on POD 7, and fluid collection at the operation site was observed on CT images. Under the diagnosis of iatrogenic dural injury, absolute bed rest and lumbar drain catheter insertion at the L2-3 level were performed for three days, but the patient continued to complain of severe headache until POD 10. We reoperated on POD 10 and observed a dural defect with CSF leakage. The surgery was completed after ensuring that the CSF leakage was resolved by dural repair. However, 10 days after the reoperation, the amount of hemovac drainage still did not decrease and was measured to be more than 250 mL. There was no improvement in the patient’s symptoms. Twenty days after the first surgery, an epidural blood patch was applied to the epidural space at the site of dural injury, and the patient’s symptoms improved.