To determine whether left ventricular (LV) global longitudinal strain (GLS) predicts adverse LV remodeling and cardiac events. In a prospective cohort study of patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI), we recorded clinical data and GLS, global circumferential strain and radial strain using two-dimensional speckle-tracking echocardiography of the left ventricle. At 6-month and 3-year follow-ups, patients were grouped by presence or absence of adverse LV remodeling. We used logistic regression to identify factors associated with adverse LV remodeling and a Cox model to determine the relationships between these factors and cardiac events. Of 97 patients (mean age 56 ± 12 years; 76 men), 38 showed LV remodeling. Diabetes mellitus [odds ratio (OR) 1.95 % confidence interval (CI) 1.2–4.8, p = 0.05], peak troponin I (OR 1.2, 95 % CI 1.1–1.3, p = 0.004), and GLS (OR 1.6, 95 % CI 1.3–2.3, p = 0.009) independently predicted LV remodeling. During follow-up (22.8 ± 12.3 months), 20 patients suffered adverse events, which were independently predicted by GLS alone (OR 4.9, 95 % CI 1.7–13.9, p = 0.002). Optimal GLS cutoffs for predicting adverse LV remodeling and cardiac events were >−12.46 % [area under receiver operating-characteristic curve (AUC) 0.88, 95 % CI 0.79–0.96, p < 0.001] and >−9.27 % (AUC 0.86, 95 % CI 0.64–0.98, p < 0.001), respectively. GLS measured immediately after primary PCI is an excellent predictor of adverse LV remodeling and cardiac events in patients with AMI.