Eleven children aged 0.6-17 years with preterminal chronic renal failure and anemia (mean serum creatinine concentration 4.8 mg/dl; mean hemoglobin concentration 7.9 g/dl) were treated with sc injections of recombinant human erythropoietin (EPO, initial dose 150 U/kg/week) over a mean period of 13 months. When a target hemoglobin concentration of 11.5-13.5 g/dl was reached, the dose was adapted. Iron deficiency was corrected. Hemoglobin concentration increased by > 2 g/dl in all patients within 14-119 (mean 45) days. The last maintenance dose ranged between 75 and 300 (mean 133) U/kg/week. No major adverse effects were observed, except for hypertension which occurred in about half of the patients and necessitated interruption of EPO in one child with advanced renal failure. Additional antihypertensive drugs were given to five patients. Body height increased in two patients by 0.6 and 1.3 SDS/year, respectively. In six patients with a mean observation period of 14 months before and 16 months after the start of EPO, the mean slope of the reciprocal serum creatinine concentration curve improved slightly (p = 0.05). The proposed schedule appears to be safe for the treatment of renal anemia in most pre-dialysis patients. Frequent monitoring of hemoglobin, blood pressure, serum creatinine and ferritin is required.