Since the first umbilical cord blood transplantation (CBT) in 1998, cord blood (CB) has now become one of the most commonly used sources of hematopoietic stem cells for transplantation. CBT has advantages of easy procurement, no risk to donor, low risk of transmitting infections, immediate availability and immune tolerance allowing successful transplantation despite human leukocyte antigen disparity. Several studies have shown that the number of cells transplanted is the most important factor for engraftment in CBT, and it limits the wide use of CB in adult patients. New strategies for facilitating engraftment and reducing transplantation-related mortality are ongoing in the field of CBT and include the use of a reduced-intensity conditioning regimen, double-unit CBT, ex vivo expansion of CB, and co-transplantation of CB and mesenchymal stem cells. Recently, the results of two international studies with large sample sizes showed that CB is an acceptable alternative source of hematopoietic stem cells for adult recipients who lack human leukocyte antigen-matched adult donors. Along with the intensive researches, development in banking process of CB will amplify the use of CB and offer the chance for cure in more patients.