Purpose: Automated function image (AFI) is a novel algorithm based on speckle-tracking imaging that can be used for assessment of left ventricular global longitudinal strain (GLS). However, its use to predict complications in patients with ST-elevation myocardial infarction (STEMI) has not been investigated. Therefore, the purpose of this study was to evaluate whether or not the GLS assessed by AFI allows noninvasive prediction of complications in patients with STEMI. Methods: The study population consisted of 105 consecutive patients with STEMI. The left ventricular GLS was measured at the time of admission. Serial CK-MB level was measured during 72 hours. Subsequent complications including cardiac death, shock, congestive heart failure during 6 months after the onset of STEMI were prospectively evaluated. Results: Complications were developed in 28 (26 %) of 105 patients with STEMI. The GLS was significantly decreased in patients who developed complications after STEMI compared with those without complications (-16.6 짹 2.2 vs -10.2 짹 3.6, p < 0.001). On the basis of receiver operating characteristic analysis, optimal cutoff values of -14 % for GLS were chosen the predictor of complication after STEMI (AUC=0.94, sensitivity=86%, specificity=88%, figure). The GLS was proportionate to infarct size which was estimated by serial CK-MB measurement. Conclusion: The GLS assessment in patients with STEMI at arrival to the hospital allows noninvasive prediction of subsequent complications.