At present nobody questions the capacity of hematopoietic progenitors (HP) from umbilical cord blood (UCB), also called hematopoietic stem cells to produce hematopoietic regeneration in patients suffering from bone marrow disease (BM). Also, the possibility of ex vivo expansion and gene therapy applied to these HP extend the therapeutic applications of UCB cells. Given the importance of these applications, the objectives of this paper are to remind health professionals of the characteristics of stem cells and their possibilities as treatment, to disseminate the correct technique for the collection and handling of UCB cells and to inform on the current legal scenario in Spain. These measures will help improve the level information that is given to those individuals of the population that might ask for information relating this subject and to promote the donation of umbilical cord blood.