After allogeneic stem cell transplantation (allo-SCT) some patients develop persistent anemia in association with an inadequate erythropoietin (Epo) secretion. We determined the frequency and risk factors for this complication and the response to treatment with erythropoiesis stimulating proteins (ESP). Of 83 evaluable allo-SCT patients, 63 (76%) developed persistent anemia at a median of 34 (range: 30-244) days after allo-SCT. Forty-one (49%) patients had anemia considered as primary, and in all of them inadequate serum Epo levels (median 43.3, range: 2.5-134, mU/mL) were found. A high creatinine level during the first month after allo-SCT was associated with primary anemia (relative risk [RR] 2.5, P = .01). Of the 41 patients, 35 received ESP. Transfusion independence and an Hb level higher than 10 g/dL was achieved in 29 of 30 (97%) evaluable patients. Median ferritin levels at the beginning and at the end of the ESP treatment was 1628 (range: 168-5208) and 805 (range: 14-7443) ng/mL, respectively (P = .04). In conclusion, anemia associated with impaired Epo secretion after allo-SCT is more frequent than usually recognized and it is associated to early postransplantation renal damage. This complication easily reverts with ESP, which seems to contribute to reduce iron overload.