Increased glycemic variability (GV) is frequently observed among patients in the intensive care unit (ICU) and is related to patient prognosis. Nevertheless, the relationship between GV and the prognosis of individuals with traumatic lung injury (TLI) remains inconclusive. This study mainly aimed to explore the association between GV and the prognosis of TLI.Clinical data of TLI patients in the ICU were obtained from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The association between GV and the risk of in-hospital mortality (IHM) in TLI patients was examined via the Cox proportional hazards (CPH) models. The potential non-linear relationship between GV and the risk of IHM was investigated through restricted cubic spline (RCS) models. Survival differences between groups were assessed by Kaplan-Meier (KM) survival analysis. Subsequently, subgroup analyses were carried out.There were 1,232 patients selected from the MIMIC-IV database. CPH analysis revealed that higher GV was notably associated with an elevated risk of IHM [hazard ratio (HR) =3.555; 95% confidence interval (CI): 1.602-7.891]. RCS analysis suggested a nearly linear relationship between GV and the risk of IHM. Additionally, KM survival analysis indicated significant differences in survival rates between different GV-based groups.The results suggested that higher GV was related to a heightened risk of IHM in TLI patients. Nonetheless, further large-scale prospective studies are needed to confirm the causal relationship.Copyright © 2025 AME Publishing Company. All rights reserved.