One of the limitations of allogeneic bone marrow transplant is the availability of HLA-compatible donors. HLA-identical or one antigen mismatched related donors can only be found for up to 40% of adult and 25% of paediatric patients in Hong Kong requiring a marrow transplant. The rest must rely on donors identified from volunteer unrelated marrow donor panels. Almost all our patients are Chinese but most volunteers in the worldwide marrow donor registries are Caucasians whose HLA profiles are different. Thus an unrelated marrow donor registry for Chinese was established in Hong Kong in 1991 and > 17,000 volunteers have participated. More than 300 local and overseas Chinese patients have so far been referred to our Registry for donor search. Suitable donors have been found ultimately for 40% of them. So far, 26 marrow transplants have been performed using unrelated donors from this registry. They include six overseas Chinese patients.