The incidence of lumbar spinal stenosis is increasing annually, and with an ever-aging population and longer life expectancies, this trend will further continue. It is hoped that a more effective treatment can be found so that the patients can be relieved of their pain. The aim of this systematic review and meta-analysis was to evaluate the effectiveness and safety of unilateral biportal endoscopic surgery (UBE) and microscopic decompression surgery (MD) for the treatment of lumbar spinal stenosis. A literature search of related studies published until April 2022 was performed using PubMed, EMBASE, Cochrane Library, Web of Science, ClinicalTrials.gov, Google Scholar, China National Knowledge Infrastructure (CNKI), and other databases. After filtering of references, 12 eligible studies were identified that compared UBE with MD as a treatment for lumbar spinal stenosis. Data were extracted and analysed using R. A total of 12 articles (four randomized controlled and eight cohort studies) were included, with a total of 1,067 patients: 250 men and 249 women in the UBE group and 290 men and 278 women in the MD group. The meta-analysis showed that the mean intraoperative blood loss in the UBE group [standardized mean difference (SMD)=-2.10, 95% confidence interval (CI) (-3.97, -0.23), P=0.03] was lower than that in the MD group. The postoperative Visual analogue scale (VAS) score for back pain [SMD=-0.52, 95% CI (-0.76, -0.27), P<0.01], leg pain [SMD=-0.30, 95% CI (-0.51, -0.08), P<0.01], postoperative Oswestry disability index [(ODI); SMD=-0.25, 95% CI (-0.48, -0.03), P=0.03], and postoperative C-reactive protein [(CRP); odds ratio (OR)=-0.92, 95% CI (-1.80, 0.03), P=0.04] were lower than those in the MD group. Complications (OR=0.60, 95% CI (0.37, 0.98), P=0.04) and hospital stay (SMD=-1.84, 95% CI (-2.85, 0.83), P <0.01] were also lesser in the UBE group than in the MD group. UBE was preferable to that in the MD group according to the modified MacNab score [OR=2.28, 95% CI (1.28, 4.06), P<0.01]. No significant differences were observed in the operation times between the groups. UBE surgery was found to be a better option for the treatment of lumbar spinal stenosis than MD surgery.