What is known and objective: Long non-coding RNAs (lncRNAs) have been proved to regulate. LncRNA TUG1 is well characterized in cancer biology. This study was carried out to investigate the molecular function of lncRNA TUG1 in myocardial infarction. Methods: This study enrolled 58 MI patients and 52 healthy volunteers, and blood samples were obtained from these participants. The expression levels of lncRNA TUG1 in plasma of MI patients and healthy volunteers were detected by qPCR. Overexpression experiments were performed to evaluate the interactions between lncRNA TUG1 and caspase 3. Results: The expression levels of lncRNA TUG1 were significantly increased in MI patients. And low lncRNA TUG1 expression group had a significantly higher overall survival rate than that of high lncRNA TUG1 expression group. Overexpression of lncRNA TUG1 promoted the apoptosis of AC16 cells and upregulated the expression of cleaved caspase- 3. What is new and results: Our study first reported the upregulation of lncRNA TUG1 in MI. Our results demonstrated that upregulation of lncRNA TUG1 effectively distinguished MI patients from the healthy controls. Therefore, upregulation of lncRNA TUG1 might serve as a potential diagnostic marker for MI. © 2020 John Wiley & Sons Ltd