SummaryBackgroundClinically, there are substantive practice variations in surgical management of degenerative lumbar spondylolisthesis. We aimed at evaluating whether decompression alone outcomes for patients with degenerative lumbar spondylolisthesis are comparable to those of decompression with fusion.MethodsIn this meta-analysis, the Embase, PubMed, and Cochrane Library databases were searched from inception to February 16th, 2022. Randomised controlled trials (RCTs) and cohort studies comparing decompression alone with decompression and fusion for patients with degenerative lumbar spondylolisthesis were included in this study. There were no language limitations. Odds ratio (OR), mean difference (MD) and 95% confidence interval (CI) were used to report results in the random-effects model. Main outcomes included Oswestry disability index (ODI), pain, clinical satisfaction, complication and reoperation rates. The study protocol was published in PROSPERO (CRD42022310645).FindingsThirty-three studies (6 RCTs and 27 cohort studies) involving 94 953 participants were included. Differences in post-operative ODI between decompression alone and decompression with fusion were not significant. A small difference for back (MD, 0.13; [95% CI, 0.08 to 0.18]; I2:0.00%) and leg pain (MD, 0.30; [95% CI, 0.09 to 0.51]; I2:48.35%) was observed on the 3rd post-operative month. The results did not reveal significant differences in leg pain and back pain between decompression alone and fusion groups on the 6th, 12th, and 24th post-operative months. Difference in clinical satisfaction between decompression alone and decompression with fusion were not significant from RCTs (OR, 0.26; [95% CI, 0.03 to 1.92]; I2:83.27%). Complications (OR, 1.54; [95% CI, 1.16 to 2.05]; I2:48.88%), operation time (MD, 83.39; [95% CI, 55.93 to 110.85]; I2:98.75%), intra-operative blood loss (MD, 264.58; [95% CI, 174.99 to 354.16]; I2:95.61%) and length of hospital stay (MD, 2.85; [95% CI, 1.60 to 4.10]; I2:99.49%) were higher with fusion.InterpretationClinical effectiveness of decompression alone was comparable to that of decompression with fusion for degenerative lumbar spondylolisthesis. Decompression alone is recommended for patients with degenerative lumbar spondylolisthesis.FundingThis work was supported by grants from the National Natural Science Foundation of China (No. 81871818), Tangdu Hospital Seed Talent Program (Fei-Long Wei), Natural Science Basic Research Plan in Shaanxi Province of China (No.2019JM-265) and Social Talent Fund of Tangdu Hospital (No.2021SHRC034).