Background: The right ventricular (RV) apex has been used for cardiac stimulation because this position is easily accessible and associated with a low dislodgement rate. This position, however, is associated with a dyssynchronous left ventricular contraction with subsequent deleterious hemodynamic effects. Alternative stimulation sites have been studied because of a potentially better hemodynamic effect compared with RV apex pacing. The purpose of this study is to compare RV outflow tract (or basal septum) with RV mid-septum on electrocardiographic and echocardiographic dyssynchrony. Subjects and Methods: We divided 37 patients into 2 groups - group I (RV mid-septal pacing, 25, M:F=16:9, 63짹14 years) and group II (RV outflow or basal septal pacing, 12, M:F=8:4, 64짹12 years). RV septum was divided into 3 sites from base to apex with right anterior oblique view during implantation of pacemaker. QRS duration at 12 lead ECG was measured just after implantation and at 1 year follow up. Echocardiographic dyssynchrony index (septal to posterior wall motion delay, septal lateral wall motion delay, preejection time difference), left ventricular dimension, ejection fraction were compared. Results: There were no differences in age, sex, indication of implantation of pacemaker was not different (sick sinus syndrome- 11 vs 7, AV block higher than 2nd degree – 14 vs 5, p=1.000, 0.495) between the 2 groups. Capture threshold, R wave sensitivity was not different between the 2 groups. QRS duration just after implantation and at 1 year follow-up was not different between the 2 groups at limb and precordial leads. There were no differences in left ventricular end-diastolic and end-systolic, left atrial dimension, left ventricular ejection fraction just after implantation (52짹6 vs 48짹8 mm, 34짹6 vs 32짹7 mm, 41짹7 vs 37짹5 mm, 63짹11 vs 64짹7%: p=0.129, 0.400, 0.091, 0.881) and 1 year follow up (53짹7 vs 49짹7 mm, 36짹9 vs 36짹10 mm, 43짹10 vs 38짹4 mm, 60짹12 vs 59짹13% : p=0.335, 0.893, 0.163, 0.758). There were no differences in septal to posterior wall motion delay, septal to lateral wall motion delay, pre-ejection time difference between the 2 groups just after implantation (78짹19 vs 57짹17 ms, 58짹30 vs 65짹30 ms, 35짹22 vs 14짹20 ms: p=0.099, 0.743, 0.160) and 1 year follow up (64짹15 vs 59짹11 ms, 56짹28 vs 60짹37 ms, 35짹24 vs 37짹25 ms: p=0.802, 0.423, 0.408). Conclusion: This study indicates no significant difference between the RV outflow tract and mid-septal pacing site in terms of electrocardiographic and echocardiographic dyssynchrony. These pacing sites equally may be considered valid alternative for RV apex pacing particularly in patients with impaired left ventricular function.