For proper erythropoietic response to r-Epo iron, folic acid and B12 vitamin are needed. Iron deficiency is the most common in uremic patients treated with r-Epo. So the aim of presented study was to measure hematological and iron status changes. Studies were carried out in 23 anemic, uremic, hemodialysis patients. They were divided into two groups, the first HDa--5 people (3W, 2M) aged 23-49 (mean 34 +/- 12) years and the second HDb 18 patients (11W, 7M) aged 21-56 (mean 38 +/- 12) years. Mean hemoglobin (HGB) before r-Epo was 6.9 +/- 1.0 g/dl in HDa, and 6.7 +/- 1.1 g/dl in HDb. r-Epo in HDa group was given during 12 weeks i.v. and afterwards s.c. for other 4 weeks with initial dose 3 x 50 u/kg b.w. (mean during 4 months 65 +/- 24 u/kg m.c. 3 times weekly). Patients from HDb group received r-Epo during 12 months only s.c. with initial dose 2000 u three times per week (mean during 12 months 26 +/- 4 u/kg m.c. 3 times weekly). Dose of r-Epo was changed accordingly to HGB concentration to keep it between 10-12 g/dl. Blood morphological parameters were monitored weekly using hematological autoanalyser Technicon H1, simultaneously an iron status indicators as iron, transferrin and ferritin were measured. An increase of HGB concentration, erythrocytes count and Ht value was observed in all patients (I-HGB 10.1 +/- 2.9, II-HGB 9.2 +/- 1.6).(ABSTRACT TRUNCATED AT 250 WORDS)