Umbilical cord blood (UCB) has been shown to contain sufficient progenitor cells to provide durable engraftment in children, and it provides an alternative stem cell source for patients without matched related or unrelated donors. We describe the preliminary results of a cohort of 16 pediatric patients with a median age of 9 years (range 3 -18) with haematological malignancies undergoing to a unrelated umbilical cord blood transplant with a reduced-intensity conditioning regimen of fludarabine, melphalan, and antithymocyte globulin. All patients achieved hematologic recovery, the median time to an absolute neutrophil count > 0.5 x 109/L was 20 days, and the median time to an unsupported platelet count > 20 x 109/L was 32 days. Acute graft-versus-host disease (GVHD) grade III-IV occurred in 37,5% of patients. The 100-day TRM was 25%, and the 1 -year disease-free survival was 58%. Our findings support the use of reduced-intensity regimen in pediatric patients with hematologic malignancies, however the incidence of acute GVHD is a little higher than that reported in other series so a better strategy for prophylaxis against acute GVHD should be implemented.