While theoretically the vasoconstriction associated with the rise in hemoglobin (Hb) level may potentially alter peritoneal transport characteristics, the effect of recombinant human erythropoietin (rHuEPO) therapy on peritoneal transport in continuous ambulatory peritoneal dialysis (CAPD) patients remains unclear. We have therefore performed a prospective study on the short-term effect of rHuEPO on the peritoneal transport characteristics in terms of the change in corrected dialysate/plasma creatinine (D/Pcr) in the fast peritoneal equilibration test (PET). Eight consecutive CAPD patients started on rHuEPO had fast PETs performed before and 4 to 6 months after the initiation of rHuEPO therapy. Another 8 CAPD patients with stable Hb levels not receiving rHuEPO served as a control group. All patients (study and control) had been on CAPD therapy for more than 3 months upon enrollment, and none had peritonitis during the study period. Patients receiving rHuEPO showed significant increase in Hb level, while the Hb levels of those in the control group remained unchanged. Neither the study nor the control group patients showed significant change in the corrected D/Pcr value over a mean observation period of 5.25 +/- 0.89 months. While rHuEPO appears to be effective in increasing the Hb level in CAPD patients, there is no significant impact on the corrected D/Pcr in the fast PET test observed in this short-term study.