Graft failure (GF) can be a fatal complication following haematopoietic stem cell transplantation (HSCT). We report four patients who developed early GF after unrelated HSCT and who subsequently received a double unrelated cord blood transplant (dUCBT) after reduced-intensity conditioning, at a median 15 d after the decision to perform a second transplant. Neutrophil recovery was observed in all four patients between day +15 and +31 with full donor chimaerism of one unit. Acute GVHD grades II–IV was observed in three patients. Three are alive, between 12 and 25 months after dUCBT. In conclusion, dUCBT is a promising procedure to treat early GF.