Abstract: Background: Among chronic kidney disease CKD patients, iron deficiency anemia is a common. The administration of iron is important during the treatment with erythropoiesis-stimulating agents (ESA). Reticulocyte hemoglobin content (RET-He) is a diagnostic marker for IDA. Measuring the RET-He can predict the iron status in respond intravenous (IV) iron supplementation in CKD patients. The current study was detect the cut-off value of RET-He as the target of iron supplementation in patients with CKD. Methods: This hospital based observational and analytical study included 50 CKD patients on hemodialysis (CKD-HD) in the maintenance phase of erythropoietin therapy and not receive any iron supplementation. Blood count, RET-He, and iron were studies for all patients. For each patients, we analyzed two samples: a baseline sample and another sample after 4 weeks of IV iron administration. The patients were classified into two groups regarding the optimal correction of anemia (OCA) after IV iron thereby; (1) patients how achieved the OCA (Hb ≥13.5 g/ in dl males and ≥12 g/dl for females); (2) patents who did not achieved the OCA compared to the baseline. Operating characteristic analysis (ROC) was used to determine the cut of value for predicting the response to iron administration achieving the OCA. Results: Out of 50 included CKD-HD patients, 33 patients achieved the OCA and only 17 patents not achieved the OCA. There was a statistical significant increase in HER-He after 5 weeks of IV iron supplementation comparing to the baseline values. ROC curve analysis a RET-He cutoff level of 26.9 pg, iron deficiency could diagnosed by a sensitivity of 70.6%, and a specificity of 51.5%. [Ayman Fathy Abd El-Halim, Jehan Saeed Abdo Soliman and Mohamed Gooda Abdelhamid. Reticulocyte hemoglobin equivalent (RET-He) as a predictor of response to intravenous iron in hemodialysis patients: A