Background: Assessment of the umbilical cord blood (UCB) unit is a crucial issue in the hematopoietic stem cell transplantation. A cord blood bank (CBB) must ensure that the final product of transplantation is represented accurately from quality control (QC) products of the UCB unit. The use of a tube segment attached to the UCB unit as well as a separate 1.8 mL cryovial containing an identical aliquot of the cryopreserved UCB unit product was exposed to the same postprocessing freezing and storage conditions as the UCB unit. Eventually, the utility of the attached segment and the 1.8 mL cryovial was evaluated as valid QC tools in order the final UCB unit graft to be validated.