Lumbar spinal stenosis (LSS) is prevalent among octogenarians, causing significant pain and disability. Surgical intervention is often required because of the ineffectiveness of conservative treatments. This study investigates the efficacy and safety of biportal endoscopic decompressive laminectomy (BED) in octogenarians with severe LSS, evaluating its potential as a minimally invasive surgical option. This retrospective study included 107 patients aged 80 years or older who underwent BED for LSS between March 2017 and December 2022. Data were collected from electronic medical records, including demographic information, clinical outcomes, and surgical details. Patients with fractures, infectious spondylitis, herniated discs, and follow-up less than 12 months were excluded. Clinical outcomes were assessed using the visual analog scale, Oswestry Disability Index, European Quality of Life-5 Dimensions, and painDETECT at baseline and at 3, 6, and 12 months after surgery. The mean age of the 107 patients was 84.1 years, with 59% being women. Significant improvements were observed in visual analog scale scores for lower back and lower extremities pain, Oswestry Disability Index, European Quality of Life-5 Dimensions, and painDETECT scores, indicating reduced pain, decreased disability, and enhanced quality of life. There were no significant differences in outcomes between patients aged 80 to 84 and those 85 or older. Surgery-related outcomes such as operation time, blood loss, and complications were similar in both age groups. BED is a safe and effective treatment for LSS in octogenarians, providing significant pain relief and functional improvement. This minimally invasive technique is also viable for patients older than 85 years, without increased risk of complications, supporting its broader indications in managing LSS in the elderly. This study highlights the efficacy and safety of BED for LSS in octogenarians, demonstrating its potential to improve quality of life and function with low risks, making it a feasible option for elderly patients.