Iron deficiency contributes to anemia after transplantation. The magnitude of iron loss from blood loss in the peri-transplantation period has not been quantified. We prospectively estimated phlebotomy and surgical losses over the first 12-weeks following transplantation in 39 consecutive renal transplant recipients on hemodialysis (HD), peritoneal dialysis (PD), or chronic kidney disease (CKD). At transplant, ferritin levels were <200 ng/ml in 51% of the patients, and iron saturation was </=20% in 44%. CKD patients more commonly had ferritin levels <200 ng/ml than either HD or PD patients (100% vs. 21% vs. 67%, P < 0.0002, respectively). Blood loss was similar among HD, PD and CKD patients (833 +/- 194 vs. 861 +/- 324 vs. 755 +/- 79 ml respectively, P = NS), and no difference between deceased and living donor transplant recipients (881 +/- 291 vs. 788 +/- 162 ml, P = 0.33). Based on baseline hemoglobin (Hgb) of 11.8 g/dl, we estimated that an additional 330 mg of iron was needed to normalize hemoglobin to 13 g/dl, and 605 mg to increase hemoglobin to 14 g/dl. Blood and iron losses over the first 12 weeks post-transplant are substantial and may warrant early administration of intravenous iron.