Introduction: Sepsis-associated acute kidney injury (SA-AKI) is a frequent and life-threatening complication in critically ill patients, associated with high morbidity and mortality. While traditional prognostic tools provide valuable risk stratification, there remains a need for practical and universally available biomarkers to identify high-risk patients early in their clinical course. The lactate/albumin ratio (LAR) has emerged as a promising candidate for this purpose. This meta-analysis aimed to comprehensively evaluate the prognostic utility of LAR in predicting mortality among patients with SA-AKI.Methods: A systematic review and meta-analysis were conducted according to PRISMA guidelines. Electronic databases (PubMed, Embase, and Web of Science) were searched through July 2025 for observational studies reporting hazard ratios (HRs) for the association between LAR and mortality in adult patients with sepsis-associated AKI. Studies were included if they reported adjusted HRs for mortality and used established criteria for sepsis and AKI. Data extraction and quality assessment were performed independently by two reviewers. Random-effects meta-analysis was used to pool effect estimates, with heterogeneity assessed by the I² statistic.Results: Six large retrospective cohort studies, encompassing over 25,000 ICU patients, were included in the quantitative synthesis. Elevated LAR at or near ICU admission was independently associated with an increased risk of mortality. The pooled hazard ratio for the highest versus lowest LAR group was 1.97 (95% CI: 1.42–2.73), indicating nearly double the risk of death for patients with the highest LAR values. The association remained robust across varying patient populations, study designs, adjustment covariates, and mortality endpoints, despite moderate to high heterogeneity (I² = 91%). Sensitivity analyses confirmed the stability of the main findings. Additional narrative synthesis of recent prospective and perioperative studies, as well as studies in related critical illness populations, further supported the generalizability of LAR as a prognostic biomarker.Conclusion: This meta-analysis confirms that the lactate/albumin ratio is a powerful, accessible, and cost-effective biomarker for early mortality risk stratification in sepsis-associated acute kidney injury. Routine LAR measurement at ICU admission can facilitate timely identification of high-risk patients, guide clinical decision-making, and improve outcomes. Prospective validation, establishment of standardized thresholds, and integration into multimodal risk prediction tools are warranted to optimize the application of LAR in critical care practice.