The applicability of the ethanol dilution (ED) technique for total body water (TBW) determination in uremic patients was studied. 73 TBW measurements were performed on 28 patients. As the basic parameters underlying the ED technique showed nearly normal values (Widmark factor r = 0.722 ± 0.0786, normal =0.710 ± 0.090 g/kg; β60 =0.121 ± 0.037, normal = 0.140 ± 0.018 g/kg × 60 min; ‘rectilinear’ course ofthe blood ethanol elimination curve), the ED technique for TBW measurements is well applicable to uremic patients. Subclinical hyperhydration was diagnosed (TBW = 57.88 ± 8.08% of body weight, normal = 52.6 ± 5.4%) in 61% ofthe cases.