IntroductionRight ventricular (RV) infarction is one of the major causes of RV contractile dysfunction. RV involvement occurs in 20-50% of inferior infarctions [1]. Patients with RV infarction associated with inferior infarction have much higher rates of significant hypotension, bradycardia requiring pacing, and in-hospital mortality compared to isolated inferior infarction [2] Occlusion of proximal dominant RCA is usually responsible for RV infarction in inferior wall myocardial infarction [3] Results: There were 35 patients with first episode of IWMI, group A (n =14 patients) and group B (n =21patients), There were significant differences between groups in TAPSE (1.28cm vs 1.98 p < 0.001), MPI-TDI (0.69±0.12 vs 0.38±0.05 p < 0.001), and in S'velocity from RV free wall ( 0.09m/s±0.02 vs 0.12m/s ±0.02 p < 0.001). It was found that S'<10cm/s is a predictor of proximal RCA lesion with sensitivity of 92.86% and specificity of 85.71%, ppv 81.25, npv 94.74. MPI-TDI>0.55 had a sensitivity of 92.86 % and a specificity of 100%, 100% PPV and 95.45% NPV. TAPSE<16mm had a sensitivity of 93%, and a specificity of 100%. Conclusion: RV indices (S' velocity, MPI-TDI and TAPSE ) are useful in predicting proximal RCA as infarct related artery in IWMI.