Patients with chronic renal failure (c.r.f.) are at high risks of death from cardiovascular diseases. It was found that successful treatment of anemia could positively influence not only patients well being but also caused some unfavourable hemodynamic changes. The aim of the study was the estimation of some morphological and functional parameters of left ventricle (lv) in dialyzed and predialyzed patients treated with r-Epo. Two groups of patients with c.r.f. were studied. The I group of 10 dialyzed patients (6 W, 4 M, mean age 34 +/- 11, weight 55 +/- 9 kg), and the II group of 9 pre-dialyzed patients (6 W, 3 M, mean age 50.6 +/- 10, weight 63 +/- 14 kg). r-Epo (Eprex Cilag AG) was administered during 6 months s.c. The I group was given initial dose 3 x 2000 u per week (mean dose 24-46 u/kg b.w./per week, the II was on 3 x 2000 u per week (mean dose 24-46 u/kg b.w./per week) subcutaneously. The doses were adjusted by Hb level in order to keep it within limits (10-12 g/dl). Hematological parameters were monitored once a week by Technicon H1. Morphology and function of the lv were evaluated using echocardiographic measurements performed by Irex IIIA system. According to prescriptions of ASE the following parameters have been assessed: lv dimension, thickness of posterior wall in diastole and systole and thickness of interventricular septum in diastole.(ABSTRACT TRUNCATED AT 250 WORDS)