Background <p>We aimed to conduct a meta-analysis of randomized controlled trials (RCTs) to examine the efficacy of biologic DMARDs in improving the clinical response of patients with polyarticular JIA.</p> Methods <p>The literature and relevant reviews were searched for published clinical studies comparing the efficacy of standard therapy without biologic DMARDs to that of biologic DMARDs in patients with polyarticular JIA. The focus was on the minimal clinical effectiveness criteria of the pediatric American College of Rheumatology (pedACR30–100), time to disease flare, remission clinical, inactive disease, and pedACR30/flare. This meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.</p> Results <p>In total, 9 randomized controlled trials were included in the study. Compared with standard therapy, treatment with biologics significantly improved PedACR70 (relative risk [RR] 1.68; 95% confidence interval [CI] 1.43–1.96; <i>p</i> &lt; 0.00001). Similarly, PedACR30 (RR 1.37; CI 1.19–1.58; <i>p</i> &lt; 0.0001), PedACR50 (RR 1.49; CI 1.25–1.77; <i>p</i> &lt; 0.00001), PedACR90 (RR 1.67; CI 1.34–2.09; <i>p</i> &lt; 0.00001) and PedACR100 (RR 1.88; CI 1.05–3.35; <i>p</i> = 0.03) were also significantly improved with biologic treatment. However, patients on standard therapy had worse flare outcomes, as determined by the PedACR30/Flare (RR 0.56; CI 95% 0.45–0.70; <i>p</i> &lt; 0.00001). Additionally, the time to disease flare was significantly shorter with standard therapy (hazard ratio [HR] 0.38; 95% CI 0.27–0.54; <i>p</i> &lt; 0.00001).</p> Conclusion <p>Compared with standard therapy, biologic DMARDs lead to significant and long-term improvements in signs and symptoms in polyarticular JIA patients.</p> Trial registration <p>This meta-analysis was registered in PROSPERO under the registration number CRD42023494938 on December 18, 2023.</p>