Purpose: Right ventricular (RV) infarction complicates one third of inferior ST segment elevation myocardial infarctions (STEMI). Our aim was to evaluate RV function to assess its in-hospital and long-term prognostic value. Methods: We enrolled 247 patients with inferior STEMI treated with primary angioplasty. Echocardiography was performed within 48 hours and after 6 months including RV myocardial performance index (RVMPI), RV fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE), RV global longitudinal strain (RVGLS), and pulmonary artery systolic pressure (PASP). Major adverse cardiac events (MACE) were reported during 6 months follow up. The patients were categorized into MACE and non-MACE groups. Results: In patients with MACE, RV diastolic dysfunction occurred earlier as evidenced by lower E‘ wave velocity (5.8 ± 1.03 vs. 9.1 ± 2.8 cm/s, P=0.04) and higher E/E‘ (10.1 ± 3.1 vs. 6.1 ± 2.3, P=0.03). After 6 months, distorted RV geometry and RV systolic dysfunction; evidenced by lower RVFAC (32.2 ± 3.6% vs. 38.06 ± 3.9%, P=0.04), lower TAPSE (14.6 ± 1.2 vs. 17.3 ± 1.7 mm, P=0.02), higher RVGLS (-14.5 ± 2.6% vs. -17.5 ± 1.2%, P=0.04) and higher PASP (29.8 ± 3.2 vs. 24.1 ± 2.2 mmHg, P=0.01), was reported later on. Multivariate analysis documented E‘ wave velocity, E/E‘, RVFAC, and TAPSE as strong predictors of MACE. Conclusion: In inferior STEMI, RV diastolic dysfunction occurs earlier in patients with MACE. However, RV systolic dysfunction and impaired RV geometry develop later on. E‘ wave velocity, E/E‘, RVFAC, and TAPSE are strong independent predictors of MACE.