INTRODUCTION The predictive value of soluble suppression of tumorigenicity 2 (sST2) for the occurrence of major adverse cardiovascular events (MACEs) in patients with ST-segment elevation myocardial infarction (STEMI) remains unclear. OBJECTIVES We aimed to investigate the role of sST2 in predicting MACEs in STEMI patients after primary percutaneous coronary intervention (pPCI). PATIENTS AND METHODS A total of 350 patients were enrolled in this study. The levels of sST2, N-terminal pro-B-type natriuretic peptide (NT-proBNP), cardiac troponin I (TnI), and creatine kinase-MB (CK-MB) were measured on admission as well as 24 hours and 5 days after pPCI. The end point was the incidence of MACEs. RESULTS Compared with the values on admission, sST2 levels increased 24 hours post pPCI and decreased significantly at day 5 after the procedure in the whole cohort. The pattern of sST2 level changes between the 3 time points was similar in the MACE and MACE-free groups. Notably, the change in the sST2 level from admission to 24 hours post pPCI (Delta(1)sST2) was significantly higher in the MACE group. After multivariable adjustment, Delta(1)sST2 was an independent risk factor for MACEs, with an area under the curve of 0.621 (95% CI, 0.547-0.695). Patients with a greater Delta(1)sST2 had a significantly higher incidence of composite MACEs, coronary revascularization, and cardiac rehospitalization. However, the change in sST2 levels from admission to 5 days post pPCI, as well as the dynamic changes in NT-proBNP, TnI, and CK-MB levels had no predictive value. CONCLUSIONS The increase in plasma sST2 levels from admission to 24 hours post pPCI has a potential value for independently predicting the incidence of coronary revascularization and cardiac rehospitalization at 1 year in patients with STEMI.