Heart rate variability (HRV) is a non-invasive method used for the assessement of autonomic modulation of heart rate. Decreased HRV is an indicator of increased cardiovascular risk. The aim of this study was to evaluate the relationship between the heart rate variability and left ventricular hypertrophy and native parathormone (iPTH) serum concentration in patients with chronic renal failure (crf) treated by hemodialysis. 24-hours ECG recording with time domain HRV evaluation, resting, transthoracic echocardiography (ECHO), were measured in 59 crf patients and in 30 healthy volunteers. Creatinine, urea, total protein, albumin, electrolytes, hemoglobin, hematocrite and iPTH serum concentration as well as body mass index (BMI) were assessed in all patients. All crf patients had decreased lower values of HRV. The correlations between SDNN, pNN50, rMSSD and parameters of LVH and with PTH serum level indicated the disturbances of the autonomic function in chronic renal patients. Left ventricular hypertrophy (LVH) in all crf patients was observed. The correlations between iPTH serum level and parameters of LVH suggest the role of PTH in the development of uremic cardiomyopathy.