Objective: To investigate the clinical efficacy of spinal endoscopic surgery for lumbar posterior ring apophysis separation (PRAS) via percutaneous transforaminal approach. Methods: A retrospective case series study was conducted to analyze the clinical data of 32 patients with lumbar PRAS admitted to the First Affiliated Hospital of Fujian Medical University from September 2016 to March 2018. There were 20 males and 12 females, aged 20-47 years [(33.7 ± 6.6)years]. All patients had single-segment lesions. The injured segments were at L_3/4 in seven patients, L_4/5 in 14 patients, L₅/S₁ in 11 patients. All patients were treated with spinal endoscopic surgery via percutaneous transforaminal approach. The incision length, operation time, intraoperative blood loss, intraoperative fluoroscopy times of C-arm X-ray machine and operational complications were recorded. At 24 hours, 3 months and 12 months after operation, the efficacy was evaluated by visual analogue score (VAS), Oswestry dysfunction index (ODI) and modified MacNab criteria. Results: All patients were followed up for 12-30 months, with an average of 15.5 months. The incision length was 7-9.5 mm [(8.0±0.9)mm], the average operation time was 60-155 minutes [(80.5±13.2) minutes], the average intraoperative blood loss was 5-25 ml [(10.6±5.7)ml] and the average number of fluoroscopy was 5-25 times [(9.4±3.4) times]. The patients were permitted to move wearing hard waist 8-12 hours after operation and returned to normal work and life 6 weeks after operation. Postoperative dysesthesia was noted in one patient, who recovered after neurotrophy and physiotherapy after one week. There were no complications such as open surgery conversion, intervertebral space infection, nerve root injury and dural sac laceration. The VAS and ODI at 24 hours, 3 months and 12 months after operation [low back pain VAS: (3.4±1.5)point, (1.8±1.1)points, (1.7±0.9)points; leg pain VAS: (1.8±1.0)points, (1.6±0.8)points, (1.4±0.6)points; ODI: (26.8±9.7)%, (13.9±4.3)%, (12.8±2.8)%] were significantly improved compared with those before operation [ back pain VAS: (7.3±2.1)points, leg pain VAS: (7.9±2.7)points; ODI: (56.2±15.6)%] (P<0.05). According to the modified MacNab criteria, the results were excellent in 25 patients, good in five patients, and fair in two patients, with the excellent and good rate of 94%. Conclusion Spinal endoscopic surgery for lumbar PRAS via percutaneous transforaminal approach is an effective method with advantages of small incision, less complications, effective pain relief and fast functional recovery.