This report reviews the author's experience and the results of a multicenter study with regard to the use of recombinant human erythropoietin (Epo) in predialysis patients. The data demonstrate that Epo corrects anemia and improves quality-of-life assessment and exercise capacity in patients who are not dialyzed, but who have renal insufficiency. The incidence of hypertension was 22% in the Epo-treated subjects and 19% in the placebo group. Within the Epo-treated group, there appears to be a greater frequency of hypertensive events in those subjects receiving the higher dosages. The concern that Epo might accelerate the deterioration of renal function is not substantiated by several clinical studies.