The use of recombinant human erythropoietin (rhuEPO) has revolutionized the treatment of renal anemia, but the dose regimens have not been established. We studied the effects of subcutaneous rhuEPO given 4,000U (1 vial) every 5-10 days in 9 patients on continuous ambulatory peritoneal dialysis (CAPD). Ten stable CAPD patients (6 females and 4 males; mean age +/- SEM, 54.4 +/- 5.6 years; mean baseline hemoglobin concentration 7.3 +/- 1.2g/dL) were commenced on s.c. rhuEPO. None of the patients had a history of gastrointestinal bleeding, aluminum overload, sepsis nor receiving androgens. Seven patients were receiving 4,000 U rhuEPO weekly, one patient each was receiving 4,000 U every 5 and 10 days (range, 66.7-89.3 U/kg/week). The dose was adjusted every 4 weeks according to response by altering the dose interval. The mean hemoglobin concentration increased from 7.3 +/- 1.2 g/dL to 10.3 +/- 1.1 g/dL over 8 weeks. There was no significant changes in the serum ferritin, urea, creatinine and potassium levels. One patient required an increase in antihypertensive therapy. We feel that s.c. rhuEPO 4,000 U given on an intermittent basis is effective in the treatment of anemia in CAPD patients. The administration of a single vial each time is convenient and cost sparing. The gradual rise in hematocrit avoids complications.