Purpose: This was a prospective study conducted at Benha University hospital and National Heart Institute on one hundred patients undwent coronary artery bypass grafting (CABG) to evaluate the effect of CABG on the right ventricular (RV) function using speckle tracking echocardiography (STE). Methods: All cases were subjected to detailed medical history, full physical examination, 12 leads electrocardiogram (ECG), routine laboratory tests including (complete blood picture, liver functions, renal functions and lipid profi le) and echocardiography either conventional echocardiography or STE, all parameters obtained before and within 2 weeks after surgery. Results: By conventional echocardiography there was statistically signifi cant decrease in peak right ventricle systolic velociy (RVS´) from (12.76 ± 1.72) to (7.33 ± 1.71) and tricuspid annular plane systolic excursion (TAPSE) from (22.8 ± 3.99) to (13.77 ± 4.63) among the studied patients after CABG. While there was signifi cant increase in right ventricle fractional area change (RVFAC) from (44.69 ± 3.25) to (49.01 ± 3.36). On the other hand, there was non-signifi cant change in right ventricle end diastolic diameter (RVEDD) at mid-cavity from (26.37 ± 2.72) to (26.53 ± 2.72) and basal segment from (36.05 ± 2.98) to (36.29 ± 3.04), right ventricle stroke volume (RVSV) from (65.44 ± 7.02) to (65.85 ± 6.86) and right myocardial performance index (RMPI) from (0.491 ± 0.088) to (0.498 ± 0.086). Statistical analysis Data analysis was performed using the software SPSS (Statistical Package for the Social Sciences) version 20.