Background: Preterm infants often receive blood transfusions early in life. In this setting, umbilical cord blood (UCB) might be safer than adult blood (A) with respect to infectious and immunologic threats. Objectives: To evaluate, as a first objective, the feasibility of fulfilling transfusion needs of preterm infants with allogeneic UCB red blood cell (RBC) concentrates and, as a secondary objective, to assess the safety of allogeneic cord blood transfusions. Methods: At the Neonatal Intensive Care Unit and the UNICATT Cord Blood Bank of 'A. Gemelli' Hospital in Rome, a prospective study was carried out over a 1-year period, enrolling newborns with gestational age ≤30 weeks and/or birth weight ≤1,500 g requiring RBC transfusions within the first 28 days of life. At first transfusion, patients were assigned to receive UCB-RBCs or A-RBCs depending on the availability of ABO-Rh(D)-matched UCB-RBC units. The same regimen (UCB-RBC or A-RBC units) was thereafter maintained, unless ABO-Rh(D)-matched UCB-RBC units were not available. Results: Overall, 23 UCB-RBC units were transfused to 9 patients; the requests for UCB-RBC units were met in 45% of patients at the first transfusion and in 78% at the subsequent transfusions. At a median follow-up of 57 days (range 6-219), no acute or delayed transfusion-related adverse events occurred. Hematocrit gain after transfusion and time intervals between transfusions were similar in the UCB-RBC and A-RBC group, as well. Conclusions: Transfusing allogeneic UCB-RBC units in preterm infants appears a feasible and safe approach, although the transfusion needs of our study population were not completely covered. More data are necessary to validate this novel transfusion practice. © 2014 S. Karger AG, Basel.