Background Atherosclerosis is a process that causes coronary artery disease and is associated with the inflammatory response. In this study, we aimed to evaluate the association of Pan-Immune-Inflammation Value (PIV) with in-hospital and long-term mortality in STEMI patients. Methods A total of 658 patients who were admitted to the emergency department of two tertiary centers with the diagnosis of STEMI and underwent percutaneous coronary intervention (PCI) between 2018 and 2022 were retrospectively enrolled. PIV and other inflammation parameters were compared for the study population. The primary outcome was one-year all-cause of mortality. Results The mean age was 58.7 +/- 17.1 years and 507 (76.9%) were male. The mean duration of the follow-up was 18.8 +/- 8.5 months (median 18.9 months). PIV was superior to the neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, and systemic immune-inflammation index for the prediction of primary and secondary outcomes in STEMI. Conclusion Our study reveals that PIV is a better predictor of mortality in STEMI patients. Prospective studies are needed to validate this biomarker.