The umbilical cord blood (UCB) compositions of the present invention possess the unique features of having plasma that is substantially depleted from the UCB unit and red blood cells (RBC) that are not depleted from the UCB unit. Such UCB units can be prepared by a process that combines plasma depletion with cryopreservation, selection, thawing, and/or transplantation of hematopoietic stem cells to provide superior clinical outcome by maximizing post-processing cell recovery and post-thaw infusion cell dose. Methods for treating a wide variety of malignant diseases and benign diseases associated with the hematopoietic system by administering the UCB compositions of the present invention are also provided.
