Introduction <p>The present study reported the first case of lumbar spinal stenosis in a patient with achondroplasia, successfully managed through endoscopic decompression.</p> Methods <p>Case report.</p> Case presentation <p>A 33-year-old achondroplastic male with a 3-month history of low back pain and right leg radicular symptoms presented to our hospital. Despite conservative treatments, his condition worsened, leading to an inability to stand or walk for more than a minute. Imaging studies revealed multilevel lumbar spinal stenosis, and a selective nerve root block confirmed the L4/5 level as the source of symptoms. He underwent unilateral biportal endoscopic decompressive surgery at L4/5, which involved minimal tissue disruption and preservation of the inner disc nucleus pulposus. Postoperatively, he experienced near-resolution of neurological symptoms and lower back pain, regaining the ability to walk normally within a day and was discharged three days post-surgery.</p> Conclusion <p>This case report highlights the effectiveness and safety of the unilateral biportal endoscopic technique for lumbar spinal decompression in individuals with achondroplasia, with a successful recovery and no radicular symptoms over a 30-month follow-up period.</p>