Objectives: We sought to investigate the influence of the extent of myocardial injury on left ventricular (LV) systolic and diastolic function in patients after reperfused acute myocardial infarction (AMI). Methods: Thirty-eight reperfused AMI patients underwent cardiac magnetic resonance (CMR) imaging afterpercutaneous coronary revascularization. The extent of myocardial edema and scarring were assessed by T2 weighted imaging and late gadolinium enhancement (LGE) imaging, respectively. Within a day of CMR, echocardiography was done. Using 2D speckle tracking analysis, LV longitudinal, circumferential strain, and twist were measured. Results: Extent of LGE were significantly correlated with LV systolic functional indices such as ejection fraction (r=-0.57, p<0.001), regional wall motion score index (r=0.52, p=0.001), and global longitudinal strain (r=0.56, p<0.001). The diastolic functional indices significantly correlated with age (r=-0.64, p<0.001), LV twist (r=-0.39, p=0.02), average non-infarcted myocardial circumferential strain (r=-0.52, p=0.001), and LV end-diastolic wall stress index (r=-0.47, p=0.003 with e`) but not or weakly with extent of LGE. In multivariate analysis, age and non-infarcted myocardial circumferential strain independently correlated with diastolic functional indices rather than extent of injury. Conclusions: In timely reperfused AMI, age and non-infarcted myocardial function rather than the extent of myocardial injury was more related to LV chamber diastolic function.