This is an international multicenter retrospective study evaluating the clinical feasibility and outcomes of living donor liver transplantation (LDLT) in patients with acute-on-chronic liver failure (ACLF). The study will analyze medical records of ACLF patients who underwent LDLT between 2013 and 2023 across multiple participating institutions, including Max Super Specialty Hospital, Saket. The primary objective is to assess short-term and long-term clinical outcomes, including graft and patient survival rates at 90 days, 1 year, and 3 years post-transplantation. Secondary objectives include identifying risk factors for futility (death within 3 months or in-hospital mortality) and developing predictive models for transplant outcomes. Data will be classified according to ACLF severity (Grade 1, 2, 3) using EASL-CLIF criteria, and statistical analysis will be performed to compare outcomes and validate predictive models. The study poses no direct risk to patients as it involves retrospective analysis of anonymized medical records, ensuring confidentiality and compliance with ethical standards. The findings will contribute to evidence-based guidelines for LDLT in ACLF patients and improve personalized prognosis assessment and survival rates.