A group of patients with severe anemia on standard hemodialysis were transferred to polyacrylnitrile hemodiafiltration (HDF), which was arranged in order to obtain an ultrafiltration rate (UF) higher than 100 ml/min. During HDF, despite a significant reduction of the dialysis time, all patients had a significant decrease of predialytic BUN and serum creatinine, and a significant improvement of anemia. Furthermore, a close direct correlation was detected between the percent increase of hemoglobin and the length of time on HDF. Therefore, high-UF HDF represents a valid dialytic strategy to improve anemic states, permitting a significant reduction of the dialysis time and, thus, offering a better life quality for the patients.