Objective To investigate the clinical efficacy of uniportal full-visualization spinal endoscopic lateral foraminoplasty for lumbar foraminal stenosis (LFS). Methods The clinical data of patients with LFS treated with uniportal full-visualization spinal endoscopic lateral foraminoplasty at Mianyang Orthopedic Hospital between January 2023 and June 2024 were retrospectively collected. The patients’ Visual Analogue Scale score, Oswestry Disability Index, lumbar CT before and after surgery, lumbar MacNab efficacy at the last postoperative follow-up, and surgical related conditions were analyzed to evaluate surgical efficacy and safety. Results A total of 58 patients were included, including 40 males and 18 females, with an average age of (67.8±8.8) years. The surgical duration was (76.6±10.6) minutes, and the hospitalization duration was (5.2±0.9) days. All patients did not experience complications such as nerve or spinal dural injury after surgery. The patients’ postoperative pain score, Oswestry Disability Index, intervertebral foramen height, width, and area all improved compared to preoperative levels (P<0.05). At the last follow-up after surgery, the excellent and good efficacy rate of lumbar MacNab was 93.1%. There were no surgical related complications during the perioperative period, and there were no reoperations during the follow-up period. Conclusion The uniportal full-visualization spinal endoscopic lateral foraminoplasty for LFS has good clinical efficacy and safety, but further large-scale, multi-center randomized controlled studies are needed in the future for further exploration.