Tissue Doppler (TD) imaging is a novel echocardiographic technique that measures myocardial velocities. However, there are sparse data on TD imaging of the right ventricular (RV) free wall in the diagnosis and prognosis of RV myocardial infarction (MI) in inferior wall left ventricular MI. Fifty patients who had left ventricular MI underwent TD echocardiography and angiography within 48 hours of MI. For diagnosis, the ability of RV TD imaging to detect RV MI was assessed using coronary angiography as the reference standard. For prognosis, the ability of TD detection of RV dysfunction to predict cardiac death or rehospitalization at 1 year was determined. For diagnosis, the univariate predictors of RV MI included RV diastolic dimension (p = 0.001), TD imaging of tricuspid annular systolic velocity (p = 0.001), and early diastolic velocity (p = 0.002). On multivariate analysis, systolic annular velocity (p = 0.04) and RV dimension (p = 0.05) predicted RV MI. For prognosis, nonculprit coronary artery disease (p = 0.003), TD imaging of RV systolic annular velocity (p = 0.005), and early diastolic velocity (p = 0.01) were among the univariate predictors of cardiac death or rehospitalization. On multivariate analysis, nonculprit coronary artery disease (p = 0.02) and TD imaging of systolic annular velocity (p = 0.04) were independent predictors of outcome. Decreased RV systolic annular velocity on TD images detects RV MI in first left ventricular acute inferior MI and predicts cardiac death or rehospitalization at 1 year.