Umbilical cord blood transplantation (UCBT) offers a viable hematopoietic stem cell source for patients with idiopathic and inherited bone marrow failure (BMF) syndromes lacking matched related donors (MRDs) or matched unrelated donors (MUDs). Although its use has declined with the rise of haploidentical transplantation, UCBT remains crucial for select patients, especially children. The approach is associated with rapid donor availability, low graft versus host disease (GvHD) risk, and favorable outcomes in matched settings. Retrospective data and prospective trials demonstrate encouraging survival, particularly with appropriate cell dose, minimal human leukocyte antigen (HLA) mismatch, and fludarabine (Flu)-based reduced-intensity conditioning (RIC) regimens. Specific syndromes such as Fanconi anemia (FA), severe aplastic anemia (SAA), dyskeratosis congenita (DC), and Diamond–Blackfan anemia (DBA) highlight distinct challenges and considerations in UCBT application. While matched sibling UCBT shows excellent outcomes, unrelated UCBT requires careful patient selection and transplant expertise. As research advances and transplant protocols evolve, UCBT remains a critical option in the curative landscape for patients with BMF syndromes.