The myocardial performance index (MPI) reflects global ventricular function. Chronic hypervolemia and uremia may negatively affect the myocardium of both ventricles. The aims of this study were to investigate how chronic renal failure (CRF) affects biventricular MPI and to determine whether preload reduction by hemodialysis (HD) affects left ventricular MPI (LVMPI) and right ventricular MPI (RVMPI) in CRE Twenty-one patients with CRF (group 1) were examined 1 hour before and 1 hour after an HD session and 17 healthy control patients (group 2) were examined once by echocardiography. The MPI for each ventricle was calculated as the sum of isovolumic time intervals divided by the ejection time. Before HD, the LVMPI of group 1 was similar to that in group 2 (R > .05), but the RVMPI of group 1 was significantly higher (P = .007). After the HD session, LVMPI and RVMPI remained unchanged (P > .05 for both). The LVMPI and RVMPI were not correlated either before or after HD in group 1 (P > .05 for both), whereas they were correlated in group 2 (r = 0.671, P = .003). Chronic renal failure causes isolated RV dysfunction, as reflected by increased RVMPI values. Preload reduction by HD does not affect LVMPI or RVMPI. Patients with CRF also do not exhibit the correlation of LVMPI and RVMPI that is observed in healthy individuals.