During pacemaker replacement most of the old leads are not suitable for recent needs or may show signs of dysfunction. These leads are difficult to extract and are therefore left-in situ. In this study 32 patients with one ventricular lead (Group I) were compared echocardiographically with 18 patients with two ventricular leads (Group II) in regard to their right ventricular (RV) hemodynamics. Mean age of the patients in each group was sixty-one years. Patients were evaluated echocardiographically after two years of lead implantation. Two groups were compared for right atrial (RA) area, RA and RV diameters, tricuspid insufficiency (TI), and intravascular and intracardiac thrombosis. There were no significant differences between the two groups in terms of RA and RV diameters, RA area, and venous and intracardiac thrombosis. In group I, 15 patients with (46.9%) grade I, 14 (43.7%) with grade II, and 3 (9.4%) with grade III TI were detected. In group II 2 patients (11.1%) with grade I, 6 (33.3%) with grade II, and 10 (55.6%) with grade III TI were detected. In conclusion, the incidence of TI was more frequent and of higher degree in group II than in group I, but this finding was hemodynamically insignificant.