This meta-analysis aimed to evaluate the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in adult sepsis patients. The study included 12 studies with a total of 10,811 patients, focusing on the association between higher NLR levels and poor prognosis. The results showed that a higher NLR was significantly associated with poorer outcomes (HR: 1.6273, 95% CI: 1.3951-1.8981), with significant heterogeneity (I² = 87.2%, p<0.0001). Sensitivity analysis identified one study as a major source of heterogeneity, and after its exclusion, the heterogeneity decreased. Subgroup analysis and meta-regression further revealed that study design and NLR testing time were key sources of heterogeneity. The analysis also indicated no significant publication bias. The study concluded that NLR is a reliable biomarker for predicting prognosis and mortality risk in adult sepsis patients, but more research is needed to confirm these findings.This meta-analysis aimed to evaluate the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in adult sepsis patients. The study included 12 studies with a total of 10,811 patients, focusing on the association between higher NLR levels and poor prognosis. The results showed that a higher NLR was significantly associated with poorer outcomes (HR: 1.6273, 95% CI: 1.3951-1.8981), with significant heterogeneity (I² = 87.2%, p<0.0001). Sensitivity analysis identified one study as a major source of heterogeneity, and after its exclusion, the heterogeneity decreased. Subgroup analysis and meta-regression further revealed that study design and NLR testing time were key sources of heterogeneity. The analysis also indicated no significant publication bias. The study concluded that NLR is a reliable biomarker for predicting prognosis and mortality risk in adult sepsis patients, but more research is needed to confirm these findings.