OBJECTIVE To compare the relationship of myocardial edema and corresponding contractile function over time in patients with reperfused acute myocardial infarction (AMI). METHODS This study was approved by the regional ethics committee; all patients gave written informed consent. Thirty-nine patients (34 men; mean age, 57 years; age range, 35-73 years) underwent T2-weighted, tagging, and late gadolinium enhancement magnetic resonance imaging at three time points after primary percutaneous coronary intervention for ST-elevation AMI. Circumferential strain, T2-weighted signal intensity, and volume of infarct zones, peri-infarct zones, and remote myocardium were measured. Patients were stratified by presence or absence of peri-infarct edema, defined as areas with T2-weighted signal intensity of two or more standard deviations above that of remote myocardium. Statistical analysis was performed with repeated-measures analysis of variance with post hoc Bonferroni correction. RESULTS Edematous peri-infarct myocardium had attenuated strain compared with remote myocardium at day 2 (-0.137 vs -0.226, P < .001), day 30 (-0.188 vs -0.240, P < .01), and day 90 (-0.207 vs -0.241, P = .01). Nonedematous peri-infarct myocardium had similar (P > .05) strain to remote myocardium at all time points. Strain improved in edematous peri-infarct myocardium at day 30 (P = .02) and day 90 (P < .01), closely mirroring resolution of intensity and volume of edema. Decreased strain correlated with edema volume (r = 0.30, P = .01) and normalized edema signal intensity (r = 0.28, P < .01). In eight patients with fully transmural infarction, infarct zone strain improved between day 2 and day 90 (P = .02). CONCLUSIONS Improvement of strain in peri-infarct myocardium closely follows regression of myocardial edema. Volume of edema and intensity of signal on T2-weighted images relate to functional recovery after reperfused AMI.