Abstract: [Objective] To explore the clinical outcomes of microscope-assisted bilateral decompression via unilateral approach for degenerative lumbar stenosis. [Methods] 40 consecutive patients who underwent single-level microscope-assisted bilateral decompression and fusion via unilateral approach for degenerative lumbar stenosis from June, 2018 to March, 2019 retrospectively. The duration of surgery, blood loss in the operation, and complications were evaluated. Clinical outcomes were assessed by the visual analogue scale (VAS) of legs, Oswestry disability index (ODI) score and modified Macnab criteria in preoperative period as well as 3,6,12 month after surgery. [Results] All patients underwent the operation, and there were no cases of switching to open or other surgical methods. The operating time was 181.33±20.21mins, and blood loss in the operation was 167.81±37.41ml. There were 3 cases of cerebrospinal fluid leakage due to dural sac tear, and 1 case of nerve root outer membrane tear. No repair was done during the operation, and the prognosis was good. The VAS of leg pain improved significantly in all the patients compared with pre-operation (P<0.05), so did the ODI. According to Macnab assessment criteria, the surgical outcome was excellent and good in 92.5% patients. [Conclusion] The microscope-assisted bilateral decompression via unilateral approach for degenerative lumbar stenosis is effective considering its minimally invasive nature.