To evaluate 2-dimensional speckle tracking echocardiography as a diagnostic and prognostic tool in patients with acute myocarditis. In this retrospective cohort study, 45 patients (age, 39 ± 15 years; 32 male) with suspected acute myocarditis and 83 healthy controls (age, 39 ± 13 years; 27 male) underwent 2-dimensional speckle tracking echocardiography. Main outcome measures were circumferential and longitudinal strain and strain rate as prognostic and diagnostic markers. Patients with myocarditis had lower circumferential strain (−13.3 ± 5.6 % vs. −22.3 ± 4 %), circumferential strain rate (−0.9 ± 0.3 vs. −1.4 ± 0.3 s⁻¹), longitudinal strain (−11.7 ± 4 % vs. −17.7 ± 1.9 %), and longitudinal strain rate (−0.7 ± 0.2 vs. −1.0 ± 0.1 s⁻¹) (all P < .001). For diagnostic purposes, longitudinal strain had the greatest area under the curve, 0.93 (optimal cutoff value, −15.1 %; sensitivity, 78 %; specificity, 93 %). Future events were defined as cardiac death, heart transplant, placement of left ventricular assist device or implantable cardioverter-defibrillator, pulmonary edema–related respiratory failure, cardiogenic shock, and rehospitalization due to cardiac events. For every 1 % decline in longitudinal or circumferential strain, the hazard ratios (95 % CIs) were 1.26 (1.10–1.47) and 1.34 (1.14–1.63), respectively; for every 0.1 s⁻¹ decline in longitudinal or circumferential strain rate, the hazard ratios (95 % CIs) were 1.43 (1.09–1.89) and 1.52 (1.19–2.01), respectively (P < .01). Kaplan–Meier curve and log-rank test showed event-free survival significantly related to these 4 measurements. In acute myocarditis, left ventricular strain and strain rate may be promising diagnostic and prognostic tools, even in patients with preserved left ventricular ejection fraction. Most importantly, this imaging technique had a role in predicting deterioration and overall event-free survival.