Background: Cardiac strains were assumed to accurately predict adverse events after acute ST-segment elevation myocardial infarction (STEMI). There are, however, some debates on it. The aim of the study was to evaluate the effects of cardiac strains obtained from cardiac magnetic resonance (CMR) on cardiac events and adverse LV remodeling.Methods: A prospective and two-center study included STEMI patients treated with primary PCI with implantation of stents. They underwent CMR before discharge. Major adverse cardiac events and LV remodeling were obtained during 6 months follow-up.Results: Between February 2015 and September 2016, 76 patients were available for the final analysis. We reported major adverse cardiac events (MACE) rate 23.7% using cardiac death, reinfarction, unplanned revascularization and heart failure as combined events in 6 months follow-up. Global longitudinal strain (GLS) can predict MACE independently, with OR=1.229 (1.087-1.390) and P=0.001. Moreover, GLS can predict LV remodeling independently, with OR=1.943 (1.133-3.334) and P=0.016.Conclusion: In patients with STEMI treated with primary PCI, CMR-determined GLS before discharge is a good predictor of MACE and adverse LV remodeling in 6 months follow-up.