BACKGROUND: Insulin resistance is common in critically ill patients. It is not known whether it is associated with the use of invasive ventilation. This study investigated the relationship between the triglyceride glycemic index (TyG) and the risk of invasive ventilator use in critically ill patients admitted to the intensive care unit (ICU). METHODS: The study utilized the Medical Information Mart for Intensive Care-IV database. All patients were divided into three groups according to the TyG index. The study employed univariable and multivariable logistic regression analysis, competing risk analysis, and 4-knot multivariate restricted cubic spline regression. ROC curves were used to determine if the TyG index improves the predictive value of disease scores. RESULTS: Out of 2196 participants, 51.9% had invasive ventilation. Multivariable logistic regression analyses and competing risk analyses revealed that the risk of Invasive ventilator use was significantly higher in the highest quartile of the TyG index. Meanwhile, the RCS analysis indicated S-typed relationships between the TyG index and invasive ventilator use, with inflection points at 9.40, respectively. The TyG index had an incremental effect on the AUC of existing severity of illness scores to predict invasive ventilation. CONCLUSION: This study shows that an increased TyG index is a significant risk factor for invasive ventilation in patients in the ICU.