Context: Pseudomeningocele is a relatively uncommon postoperative complication of spine surgery. Although the condition tends to be asymptomatic and self-limiting, it may cause radicular pain and neurological defect due to herniation of the nerve root or the spinal cord. Its pathophysiology remains unclear. Only few cases with intraoperative photos have been reported. Finding: We present a case of pseudomeningocele with nerve root entrapment after percutaneous endoscopic lumbar discectomy (PELD). A 52-year-old man had undergone PELD for sciatic pain and showed good postoperative recovery. Unfortunately, he was readmitted for progressive right leg pain at six weeks after the surgery. After the failure of conservative therapy, he received PELD again to explore the surgical site. Intraoperatively, a pseudomeningocele-containing nerve root, herniating through a small defect in the dural sac, was identified. During the dissection process, the pseudomeningocele was broken, which led to entrapment of the nerve root. Thereafter, the microsurgical technique was adopted to relocate the nerve root into the thecae sac and to repair the dural tear by non-resorbable suture. Conclusion: To our knowledge, this case report is the first documented instance of identification of a pseudomeningocele under an endoscope, and provides insights into the transformation of a pseudomeningocele into a cerebrospinal fluid fistula with nerve root entrapment. For neurological deficit caused by pseudomeningocele following PELD, operative revision by the microsurgery technique is the appropriate strategy. © 2018, © The Academy of Spinal Cord Injury Professionals, Inc. 2018.