At the time of renal transplantation, erythropoiesis-stimulating agents and iron supplementation are routinely discontinued in the prospect of recovery of renal function. This recovery, however, is often delayed and suboptimal. In addition, blood loss because of frequent diagnostic phlebotomies may be substantial. Renal transplant recipients may thus be considered at high risk of anemia in the immediate post-transplant period. We performed a single-center observational study, including 391 recipients of a single kidney. Hemoglobin levels and parameters of iron metabolism were monitored during the immediate post-transplant period, i.e., the first 3 months after transplantation. Hemoglobin levels decreased by 3.8 ± 1.5 g/dl to reach a nadir of 9.1 ± 1.2 g/dl at day 7. Transient severe anemia was observed in 91.3% of the patients. Donor age, gender, renal diagnosis of polycystic disease, pretransplant hemoglobin and ferritin level, estimated glomerular filtration rate at month 3, and duration of initial hospitalization were observed to be independently associated with the hemoglobin level at month 3. Transient severe anemia is an almost universal observation in incident renal transplant recipients. Poor graft function, high donor age, and low iron stores are independently associated with low hemoglobin levels at month 3.