The aim of the study was to evaluate, before and after hemodialysis (HD), the effects of partial correction of anemia with erythropoietin on: cardiac index (CI), stroke index (SI), heart rate (HR), ventricular ejection index (EVI), mean arterial pressure (PAM) and systemic vascular resistance index (SVRI). Cardiac parameters were gathered by means of transthoracic bioimpedance (BoMed). Twelve patients (6 M, 6 F) aged 50.6 +/- 5 years, on HD for 92.8 +/- 15.9 months, were studied twice (basal, end of follow-up). Before rHuEPO therapy, 6 patients had a "pathologic" cardiac response to HD (defined as an increase of CI despite the reduction of pre-load). After rHuEPO, 5 out of 6 patients with a "pathologic" response reverted to a "normal" response, and 1 hypertensive patient from a "normal" to a "pathologic" response. The EVI, CI and SI of patients with "pathological" response significantly improved after rHuEPO as compared with pre rHuEPO values (EVI 1.36 +/- 0.14 vs 1.07 +/- 0.08, p = 0.023; CI 3.18 +/- 0.24 vs 1.78 +/- 0.27, p less than 0.01; SI 43 +/- 3.7 vs 24 +/- 3.8, p less than 0.01). In conclusion, partial correction of anemia with rHuEPO induces an improvement of myocardial performance, without significant hemodynamic adverse effects. Our results suggest also that anemia could play a significant role in the pathogenesis of myocardial disfunction in HD patients.