Triglyceride and glycose (TyG) index has been viewed as a reliable surrogate of cardiovascular disease (CVD) risk. We hypothesized that elevated TyG index is associated with increased risk of subclinical myocardial injury (SC-MI).A total of 6093 participants without history of CVD were extracted from the third National Health and Nutrition Examination Survey (NHANES III). SC-MI was defined by cardiac infarction/injury score (CIIS) ≥10. Multivariate logistic regression was performed to examine the association between TyG index (as a qualitative or quantitative variable) and SC-MI. TyG index was positively correlated with CIIS (β = 0.54; p = 0.004) in the multivariable linear regression analysis. In a multivariable model, TyG index was independently associated with an increased risk of SC-MI (OR = 1.17, 95% CI: 1.05 to 1.30; p = 0.004). Also, TyG>9.00 increased the risk of SC-MI (OR = 1.21, 95% CI: 1.03 to 1.43; p = 0.024) independent of other risk factors.Elevated TyG index increases the risk of CIIS and SC-MI, which could be a new biomarker in the clinical practice.