In recent years, umbilical cord blood (UCB) has emerged as a feasible alternative source of hematopoietic progenitors (CD34+) for allogeneic stem cell transplantation, mainly in patients who lack HLA-matched related marrow donors. Since the first unrelated donor transplant in 1993 more than 3500 patients have received unrelated UCB transplants for a variety of malignant and non-malignant diseases. At the Hospital San Vicente de Paúl in Medellı́n,Colombia, 12 patients, 10 children and two adults have been transplanted with unrelated UCB since 2001. 8 patients had no-malignant bone marrow diseases and 4 had malignant diseases. Median age was 9.5 years (1-28). Unrelated UCB units were provided by The New York Blood Center. Nine cord units were HLA-matched 4/6, two 5/6 and three 6/6. Two adults received more than one unit. Conditioning regimens were non-myeloablative in 4 cases and in 8 busulfan-cyclophosphamide-ATG/ TBI-cyclophosphamide-fludarabine-ATG. The median cryopreserved nucleated cell dose in children was 67.6 × 106 (35.7-165.7 × 106) and in the adult patients 42.1 × 106 (30-54.1 × 106). Engraftment occurred in 7/10 of the assessable cases (70%). Median time of neutrophil and platelet recovery (ANC >500/dl and PTL >20000/dl untransfused) was 24 days (19-34) and 35 days (28-58) respectively. Of the recipients who engrafted, 2/7 (28%) patients developed aGvHD grade 0-II and one (14%) grade III-IV. One of these patients had limited cGvHD. Full chimerism was detected in all alive patients day +100 but one who had acquired aplastic anemia with initial autologous recovery and late relapse. Median follow-up time was 22 months (6-54 months). 5/12 (42%) of patients are alive and in good conditions. Treatment related mortality occurred in 4/12 (30%) of the cases, 2 patients died due to relapse and one of disseminated M. bovis BCG infection on day +243. Although limited, this experience is encouraging and demonstrates that UCB transplantation is feasible in developing countries such as Colombia and correlated with the previously reported data. In recent years, umbilical cord blood (UCB) has emerged as a feasible alternative source of hematopoietic progenitors (CD34+) for allogeneic stem cell transplantation, mainly in patients who lack HLA-matched related marrow donors. Since the first unrelated donor transplant in 1993 more than 3500 patients have received unrelated UCB transplants for a variety of malignant and non-malignant diseases. At the Hospital San Vicente de Paúl in Medellı́n,Colombia, 12 patients, 10 children and two adults have been transplanted with unrelated UCB since 2001. 8 patients had no-malignant bone marrow diseases and 4 had malignant diseases. Median age was 9.5 years (1-28). Unrelated UCB units were provided by The New York Blood Center. Nine cord units were HLA-matched 4/6, two 5/6 and three 6/6. Two adults received more than one unit. Conditioning regimens were non-myeloablative in 4 cases and in 8 busulfan-cyclophosphamide-ATG/ TBI-cyclophosphamide-fludarabine-ATG. The median cryopreserved nucleated cell dose in children was 67.6 × 106 (35.7-165.7 × 106) and in the adult patients 42.1 × 106 (30-54.1 × 106). Engraftment occurred in 7/10 of the assessable cases (70%). Median time of neutrophil and platelet recovery (ANC >500/dl and PTL >20000/dl untransfused) was 24 days (19-34) and 35 days (28-58) respectively. Of the recipients who engrafted, 2/7 (28%) patients developed aGvHD grade 0-II and one (14%) grade III-IV. One of these patients had limited cGvHD. Full chimerism was detected in all alive patients day +100 but one who had acquired aplastic anemia with initial autologous recovery and late relapse. Median follow-up time was 22 months (6-54 months). 5/12 (42%) of patients are alive and in good conditions. Treatment related mortality occurred in 4/12 (30%) of the cases, 2 patients died due to relapse and one of disseminated M. bovis BCG infection on day +243. Although limited, this experience is encouraging and demonstrates that UCB transplantation is feasible in developing countries such as Colombia and correlated with the previously reported data.