Left ventricular function is impaired in long-term maintenance dialysis as a consequence of several inter-related conditions. Aim of the study was to assess if different degree of malnutrition can affect diastolic and systolic function of dialysis patients. Bio-electrical whole-body multifrequency impedance analysis (BIA) allows a dynamic assessment of body composition according to a multi-compartment model. This allows an assessment of lean (FFM) and fat mass (FAT), metabolically active cell mass (BCM) and a BIA Nutritional Index (NI). We studied 73 patients (53 M, 20 F), aged 54.41 +/- 3.1 yrs, on maintenance bicarbonate dialysis since 57.3 +/- 61.8 mths, by BIA, performed before and after a dialysis. I-PTH and serum albumin are correlated (r = -0.55, p < 0.001); the same trend is shown by I-PTH vs fat free mass (r = -0.47, p < 0.001) and vs NI (r = -0.51, p < 0.001). Ejection fraction (EF) is correlated with age (r = -0.50, p < 0.001) and with I-PTH (r = -0.59, p < 0.001). Moreover, albumin and EF are closely related (r = 0.36, p < 0.01), as well as EF vs FFM (r = 0.47, p < 0.001), and EF vs NI (r = 0.37, p < 0.01). A/E ratio, assumed as index of left ventricular diastolic function, shows a correlation vs albumin (r = -0.33, p < 0.01), BCM (r = -0.34, p < 0.01) and NI (r = -0.40, p < 0.01), but not with I-PTH. Malnutrition, defined both by BIA measurements and lower serum albumin, could exert unfavourable effects on left ventricular systolic and diastolic function of patients on long-term haemodialysis, even independently by hyperparathyroidism.